President Trump took a defiant victory lap in the House chamber on Tuesday night, using his address to a joint session of Congress to promote the flurry of drastic changes to domestic and foreign policy that his administration has made in just the first six weeks.

Delivering the longest address to Congress in modern presidential history, Mr. Trump reprised many of the themes that animated his campaign for president and spent little time unveiling new policies, as presidents traditionally have done on these occasions. He spoke for roughly one hour 40 minutes.

“We have accomplished more in 43 days than most administrations accomplish in four years or eight years — and we are just getting started,” he said.

Democrats lodged protests throughout the evening, with one representative getting kicked out and others holding signs in silent opposition. But Mr. Trump argued that it was the Democrats who left him a country besieged by crises and that his administration was working to clean them up.

Here are six takeaways from Mr. Trump’s first address to a joint session of Congress in his second term.

Trump signaled a reset with Ukraine after his explosive meeting with that country’s president.

One day after Mr. Trump temporarily suspended the delivery of U.S. military aid to Ukraine, he signaled a willingness to reset the relationship. The president said he appreciated a message from President Volodymyr Zelensky of Ukraine, in which he said his country was “ready to come to the negotiating table as soon as possible to bring lasting peace closer.”

The new posture comes days after Mr. Trump’s explosive Oval Office meeting with Mr. Zelensky, which resulted in the Ukrainian leader hastily departing the White House without signing a deal for the United States to have access to Ukraine’s revenue for rare earth minerals. In his message, which was posted on social media on Tuesday, Mr. Zelensky said he was ready to sign the deal, a top priority for Mr. Trump.

On Tuesday night, Mr. Trump also said he had had “serious” discussions with Russia and they have signaled they also are “ready for peace.”

“It’s time to stop this madness,” he said. “It’s time to halt the killing. It’s time to end the senseless war. If you want to end wars, you have to talk to both sides.”

Trump reiterated his support for tariffs, despite early market turmoil.

Mr. Trump widened his trade wars on Tuesday when he instituted sweeping tariffs on imports from Canada, Mexico and China. Despite the markets’ plunging in response to his actions, Mr. Trump said he would not budge, dismissing the reaction as “a little disturbance.” He said more tariffs would go into effect on April 2.

“Other countries have used tariffs against us for decades, and now it’s our turn to start using them against those other countries,” he said.

Earlier in the day, Howard Lutnick, the commerce secretary, said Mr. Trump could announce a new trade deal with Mexico and Canada as soon as Wednesday. But the president made no mention of that in his speech on Tuesday night.

“Whatever they tariff us, other countries, we will tariff them,” he said. “That’s reciprocal, back and forth.”

Trump faced sustained opposition from Democrats throughout a contentious night.

Within the first few minutes of Mr. Trump’s speech, Representative Al Green, Democrat of Texas, stood up and started heckling the president. After Mr. Green ignored multiple warnings from Speaker Mike Johnson, Mr. Johnson ordered the sergeant-at-arms to remove Mr. Green from the chamber.

Mr. Green’s eviction marked the most contentious moment of a combative night, as Democrats organized various protests against the president. Many Democratic lawmakers held up small black signs with phrases that included “Save Medicaid,” “Musk Steals” and “False.” Representative Rashida Tlaib of Michigan held up a whiteboard that said “Start by paying your own taxes” as Mr. Trump talked about tax cuts. A number of Democrats, including Representatives Maxwell Frost of Florida and Jasmine Crockett of Texas, walked out during Mr. Trump’s speech.

But even as they expressed their dissent, Democrats showed they were still struggling to coalesce around a unified message of opposition to Mr. Trump.

Trump stressed his support for Elon Musk’s efforts to overhaul government.

Mr. Musk, the world’s richest man, has overseen the Trump administration’s aggressive effort to overhaul the federal government with sweeping cuts to the work force and contracts. The speed and the scope of Mr. Musk’s work has caught many in Washington off guard, with Democrats accusing him of violating congressional spending authority and civil service protections.

But Mr. Trump made clear on Tuesday that he wholeheartedly supported Mr. Musk’s radical approach.

“He’s working very hard,” Mr. Trump said of Mr. Musk, who nodded and beamed in response. “He didn’t need this. He didn’t need this. Thank you very much. We appreciate it.”

Pointing to Democrats, he said: “Everybody here — even this side appreciates it, I believe. They just don’t want to admit that. Just listen to some of the appalling waste we have already identified.”

The president spent several minutes listing off a wide range of programs Mr. Musk’s team has cut, bragging that the effort had identified “hundreds of billions of dollars of fraud.” But even Mr. Musk’s initiative has claimed to have generated only $105 billion in savings, assertions that have not been verified. The New York Times has found that DOGE has erroneously reported savings based on contracts that had already ended and miscalculated numbers.

Mr. Trump also re-upped his attacks on federal workers, vowing to “reclaim power from this unaccountable bureaucracy.”

“Any federal bureaucrat who resists this change will be removed from office immediately,” he said.

Trump spent little time discussing new policies.

Presidents often use addresses to a joint session of Congress to lay out their agenda for the year ahead. But not Mr. Trump. He did not unveil new policies, and devoted little time to the wars in Ukraine and Gaza, both of which Mr. Trump has vowed to end.

Mr. Trump also did not address another time-sensitive issue: how to prevent the government from shutting down next week. Even with Republicans controlling the House and the Senate, there are still disagreements about the best ways to proceed on the funding battle.

The president reiterated that he wanted Congress to allocate more money for immigration enforcement while cutting taxes, but how lawmakers will achieve that remains unclear.

Trump is still re-litigating the 2024 presidential campaign.

Mr. Trump is always in need of an opponent, and for now, it appears former President Joseph R. Biden Jr. is still in his cross hairs. Even after winning the election in November, defeating Kamala Harris, Mr. Trump mentioned his predecessor’s administration more than a dozen times and called Mr. Biden “the worst president in American history.”

He blamed Mr. Biden for a litany of problems, including the high costs of eggs, crime and drugs flooding across the border, and accused him of being weak on China.

At times, Mr. Trump appeared to be giving one of his stump speeches from the campaign trail, as he railed against Mr. Biden’s immigration policies, support of transgender rights and “wokeness.”

“Wokeness is trouble. Wokeness is bad,” Mr. Trump said, without specifying what exactly he was referring to. “It’s gone. It’s gone.”

Minho Kim and Chris Cameron contributed to this report.