President Trump said on Monday that he would crack down on countries that bought Venezuela’s oil by imposing tariffs on goods those nations sent into the United States, claiming that Venezuela has “purposefully and deceitfully” sent criminals and murderers into America.

In a post on Truth Social, the president said countries that purchased oil or gas from Venezuela would be forced to pay a tariff of 25 percent on any exports they sent to the United States, starting April 2.

This unconventional use of tariffs could further disrupt the global oil trade as buyers of Venezuelan oil and gas seek alternatives. The United States and China have been the top buyers of Venezuelan oil in recent months, according to Rystad Energy, a research and consulting firm. India and Spain also buy a small amount of crude from the South American country.

But in the case of China, Venezuela’s oil makes up such a small portion of the country’s imports that the threat of higher tariffs will probably cause China to look elsewhere for oil, said Jorge León, a Rystad Energy analyst.

American purchases of Venezuelan oil are poised to wind down after the Trump administration said it would revoke a license that allowed Chevron to produce oil there.

But as Mr. Trump threatened steeper tariffs on other countries, his administration on Monday gave Chevron, the second largest U.S. oil company, another two months to produce oil in Venezuela and sell it to the United States. The administration had earlier ordered Chevron to wind down its operations by April 3.

The U.S. and Venezuelan governments have been sparring over Mr. Trump’s plans to deport migrants from the United States. Venezuela announced on Saturday that it had reached an agreement with the Trump administration to resume accepting deportation flights of migrants who were in the United States illegally.

“Venezuela has been very hostile to the United States and the Freedoms which we espouse,” the president wrote. “Therefore, any Country that purchases Oil and/or Gas from Venezuela will be forced to pay a Tariff of 25% to the United States on any Trade they do with our Country.”

Mr. Trump is planning to impose new tariffs globally on April 2, when he will introduce what he is calling “reciprocal tariffs.” He has said the United States will raise the tariffs it charges on other countries to match their levies, while also taking into consideration other behaviors that affect trade, like taxes and currency manipulation. The president has taken to calling this “liberation day,” a label he repeated on Monday.

Mr. Trump called the new levies he threatened on buyers of Venezuelan oil “secondary tariffs.” They would be an unusual use of tariffs, and it’s not entirely clear how they would work. Some trade and sanctions experts said existing secondary sanctions associated with countries such as Russia and Iran already weren’t well enforced, and questioned whether the United States would have the capacity to pull off new tariff-based penalties.

“Given the limited enforcement of existing secondary sanctions, where we have a precedent, I’m not sure how realistic effective deployment of this strategy is,” said Daniel Tannebaum, a partner at the consulting firm Oliver Wyman and senior fellow at the Atlantic Council, a Washington think tank.

But the strategy could help the United States to avoid putting financial sanctions on foreign banks that could threaten financial stability. Using tariffs could help the United States to be seen as taking tough action without incurring those risks.

With typical secondary sanctions, individuals or companies cannot buy oil or other products under sanctions from a blacklisted country. Otherwise, businesses could be subjected to U.S. sanctions themselves, facing fines or being cut off from the U.S. financial system.

But Mr. Trump and his advisers have said they think such sanctions can threaten the pre-eminence of the dollar if they are overused, by encouraging other countries to find alternative currencies. They have talked about using tariffs instead.

In his confirmation hearing in January, Scott Bessent, the Treasury secretary, said tariffs, in addition to raising revenue and rerouting supply chains, could provide an alternative to traditional financial sanctions.

Mr. Trump “believes that we’ve probably gotten over our skis a bit on sanctions and that sanctions may be driving countries out of the use of the U.S. dollar.” Tariffs could be used instead, Mr. Bessent said.

The Netflix co-founder Reed Hastings wants more researchers and students to ask deep questions about artificial intelligence and its potential to upend human norms.

To that end, Mr. Hastings has donated $50 million to Bowdoin College, his alma mater, to create a research initiative on “A.I. and Humanity” — the largest gift to the liberal arts college in Maine since its founding in 1794, the school announced on Monday.

The aim of the program, Mr. Hastings and school officials said, is to make Bowdoin a mecca for studying the risks and consequences of A.I. The initiative also aims to help prepare students to grapple with emerging technologies that can manufacture humanlike texts and even produce formulas for potential new drug compounds.

The idea for the program grew out of discussions over the last few months between Mr. Hastings and Bowdoin’s president, Safa R. Zaki, a cognitive scientist, they said. Bowdoin plans to use part of the money to hire 10 faculty members and to support professors “who want to incorporate and interrogate A.I.” in their teaching and research.

In an interview, Mr. Hastings said it was urgent for more researchers to tackle such questions because of the speed of A.I. advances and the significant disruptions the systems could bring to human endeavors like work and relationships.

“We’re going to be fighting for the survival of humanity and the flourishing of humanity,” Mr. Hastings said. He compared A.I. to social networks, noting that social networking had grown so fast that few people initially understood the changes it might bring to human interactions and behavior.

“The A.I. change, I think, will be much bigger than the social networking change,” Mr. Hastings added. “So it’s important to get started early before we’re overwhelmed by the problems.”

Dr. Zaki said she hoped Bowdoin faculty members and students would study fundamental questions about A.I. and come up with ethical frameworks for their use.

“What does it mean to have a technology that consumes so much power? What does it mean to have a technology that may widen inequities in society?” Dr. Zaki asked. “We have a moral imperative, as educators, to take this on, to confront A.I.”

Hundreds of millions of people have begun using A.I. for tasks like finding information, producing emails and generating computer code. Developers of such tools say even more powerful A.I. systems are poised to radically alter daily life.

Some prominent Silicon Valley leaders have promoted rosy visions of an A.I.-driven future.

The new initiative at Bowdoin, where Mr. Hastings received a bachelor’s degree in 1983, is aimed at more concretely studying how A.I. might alter society, for better or for worse. Mr. Hastings said he hoped the new program would also help ensure that the technology’s development served and benefited people.

“I’m an extreme techno-optimist and view most of human progress as technology progress on one side and moral-ethical systems on the other side,” he said. “The tech progress is moving ahead very nicely. Our moral-ethical system improvements need some bolstering.”

The George Foreman Lean Mean Fat Reducing Grilling Machine was the kitchen appliance America didn’t know it needed.

When it arrived in the mid-1990s, Food Network and food blogging had just been born. Martha Stewart was redefining home entertaining, and Richard Simmons had made low-fat fun. Salsa was outselling ketchup for the first time, a reflection of the country’s changing demographics and its surging interest in food and cooking.

Mr. Foreman, who had left boxing and became an evangelical preacher, was making money as a pitchman for Doritos and mufflers. He wasn’t an instant convert to the grill. An early model that the Salton company shipped him, as it searched for a spokesman, sat unused until his wife, Mary, pulled it out and made a couple of hamburgers.

Mr. Foreman agreed to let Salton, a manufacturer of juice extractors and pasta makers, slap his name on the grill, and by 1996 it had sold $5 million worth. The company would go on to sell more than 100 million of the appliances.

The George Foreman Grill infused itself into all layers of society. It became a dorm-room staple and a star on late-night television. Chefs at the sprawling Tavern on the Green in New York City set one up near the dining room to quickly grill tuna steaks for salade niçoise. Jimmy Breslin, the tough-talking newspaper columnist from Queens, kept one on the counter in his New York apartment and raved about it to visitors.

Mr. Foreman, who died on Friday at age 76, provided the magic that Salton needed to sell its recent acquisition, a countertop appliance with two nonstick metal grill plates held together with a floating hinge that could close over a beef patty and cook it in about two minutes.

And here was the real innovation: The grooved grilling surface was pitched 20 degrees so the fat would drain from the meat into a little plastic tray.

Low-fat food was wildly popular then, along with a newfound appreciation for cooking, especially for a generation that began toting the little grills to dorm rooms and first apartments.

Teri Anulewicz, a Georgia politician, was among them. Like countless young people just starting out on their own, she had received a George Foreman as a gift. In her first Atlanta apartment, which had no vent hood and no dishwasher, she pressed countless chicken breasts coated in Paul Prudhomme’s Meat Magic between those metal plates.

“I was a young woman,” she said, “who knew, thanks to always reading Cooking Light, that the boneless skinless chicken breast sat at the very top of the food pyramid for young women on a nonprofit salary.”

The George Foreman had a macho appeal, too. It played into the man-at-the-grill cliché, but was also a gateway appliance for young men looking to join a food revolution that was gaining traction.

The grill was also practical for vegetarians, who discovered that it kept 1990s-era vegetarian burgers from falling apart.

But its runaway success owed as much to its pitchman: a grinning former heavyweight champion of the world, dressed in an apron and a necktie. The infomercial was the perfect vehicle for Mr. Foreman, who mixed a preacher’s charisma and unabashed need to earn money with international fame to create a hit.

“You get all the flavor and you knock out the fat,” he’d say. “Tell them the king of the grill sent you.”

The celebrity chef Bobby Flay started watching boxing as a kid during the golden age of the heavyweight bout, when Mr. Foreman and Muhammad Ali and Joe Frazier were superstars. He remembers what a revelation it was that a boxing champion could be the face of grilling.

“It made no sense, except it made perfect sense,” Mr. Flay said in an interview on Saturday. “His personality was so unbelievably infectious.”

The grill itself was pretty ingenious, too. “It was really the first American version of the panini machine,” he said.

Line extensions followed, including a cookbook, a version just for quesadillas and a grill with a colorful plastic dome that served as a bun warmer.

Mr. Foreman earned a hefty cut of the royalties from grill sales. “There were months I was being paid $8 million per month,” he told the A.A.R.P. magazine in a 2014 interview. He and his partners sold their slice of the business in 1999 for an estimated $137.5 million.

The grill’s cultural cachet endures. The writer, actor and producer Mindy Kaling made it the star of a 2006 episode of “The Office.” The bumbling lead character, Michael Scott, burns his foot on one he kept next to his bed so he could make bacon for breakfast more efficiently.

Fancier appliance makers now sell versions that can cost nearly $200. And the George Foreman Grill company produces models that are smokeless, submersible or designed to grill 15 burgers outdoors.

But the 1995 model remains the classic. You can see one at the Smithsonian National Museum of American History, near the first microwave, the Rival Crock-Pot and Julia Child’s complete kitchen.