Hendrik Dierendonck, a second-generation butcher who has become, as he describes it, “world famous in Belgium” for his curated local beef, thinks Europe’s way of raising cattle results in varied and delicious cuts that European consumers prize.

“They want hormone-free, grass-fed,” Mr. Dierendonck explained recently as he cut steaks at a bloody chopping block in his Michelin-starred restaurant, which backs onto the butchery his father started in the 1970s. “They want to know where it came from.”

Strict European Union food regulations, including a ban on hormones, govern Mr. Dierendonck’s work. And those rules could turn into a trade-war sticking point. The Trump administration argues that American meat, produced without similar regulations, is better — and wants Europe to buy more of it, and other American farm products.

“They hate our beef because our beef is beautiful,” Howard Lutnick, the commerce secretary, said in a televised interview last month. “And theirs is weak.”

Questions of beauty and strength aside, the administration is right about one thing: European policymakers are not keen on allowing more hormone-raised American steaks and burgers into the European Union.

Further opening the European market to American farmers is just one ask on a laundry list of requests from the Trump team. American negotiators also want Europe to buy more American gas and trucks, to change their consumption taxes and to weaken their digital regulations.

Trade officials within the European Union are willing to make many concessions to avert a painful and protracted trade war and to avert higher tariffs. They have offered to drop car tariffs to zero, to buy more gas and to increase military purchases. Negotiators have even suggested they could buy more of certain agricultural products, like soy beans.

But Europeans have their limits, and those include America’s treated T-bones and acid-washed chicken breasts.

“E.U. standards, particularly as they relate to food, health and safety, are sacrosanct — that’s not part of the negotiation, and never will be,” Olof Gill, a spokesman for the European Commission, the E.U. administrative arm, said at a recent news conference. “That’s a red line.”

It is not clear how serious the Americans are about pushing for farm products like beef and chicken. But the topic has surfaced repeatedly. When U.S. officials unveiled a trade deal with Britain on Thursday, for instance, beef was part of the agreement.

But according to Britain, the deal would simply make it cheaper for Americans to export more hormone-free beef to the country and would not weaken British health and safety rules, which are similar to those in the E.U.

When it comes to the European Union, the United States can already export a large amount of hormone-free beef without facing tariffs, so an equivalent deal would do little to help American farmers.

But diplomats and European officials have repeatedly insisted that there is no wiggle room to lower those health and safety standards. And when it comes to meat-related trade restrictions more broadly, there is very little. Chicken, for instance, faces relatively high tariffs, and there is limited appetite to lower those rates.

That’s because Europe is protective of both its food culture and its farms.

Where America tends to have massive agricultural businesses, Europeans have maintained a more robust network of smaller family operations. The 27-nation bloc has about nine million farms, compared with about two million in the United States.

Subsidies and trade restrictions help to keep Europe’s agricultural system intact. The European Union allocates a big chunk of its budget to supporting farmers, and a mix of tariffs and quotas limit competition in sensitive areas. E.U. tariffs on agricultural products are around 11 percent overall, based on World Trade Organization estimates, though they vary hugely by product.

And the bloc could place higher tariffs on U.S. farm goods if trade negotiations fall through. Their list of products that could face retaliatory levies, published Thursday, includes beef and pork, along with many soy products and bourbon.

But it’s not just tariffs limiting European imports of American food. Strict health and safety standards also keep many foreign products off European grocery shelves.

Take beef. Mr. Dierendonck and other European farmers are banned from using growth stimulants, unlike in the United States, where cattle are often raised on large feedlots with the use of hormones. European safety officials have concluded that they cannot rule out health risks for humans from hormone-raised beef.

To Mr. Dierendonck, the rules also fit European preferences. The lack of hormones results in a less homogenous product. “Every terroir has its taste,” he explains, describing the unique “mouth feel” of the West Flemish Red cow he raises on his farm on the Belgian coast.

But farming beef without hormones is more expensive. And American exporters have to adhere to hormone limitations when they send steaks, hamburgers or dairy products to E.U. countries, which European farmers argue is only fair. Otherwise, imports produced using cheaper methods could put European farmers out of business.

“We cannot accept import products that do not meet our production standards,” said Dominique Chargé, a cattle farmer from the west of France who is also president of La Coopération Agricole, a national federation representing French agricultural cooperatives.

The result is that the United States does not sell much beef to Europe. It makes more economic sense for U.S. farmers to sell into markets that allow hormone-raised cattle.

One frequent American complaint is that European health standards are more about preference than actual health.

American scientists have called the risks of hormone use in cows minimal. And though E.U. officials and consumers frequently sneer at America’s “chlorinated chickens,” that rallying cry is a bit dated. American farmers have for years been using a vinegar-like acid, and not chlorine, to rinse poultry and kill potential pathogens.

Some studies in Europe have suggested that such treatments are not a replacement for raising a chicken in a way that makes it pathogen-free from the start. American scientists have concluded that the rinses do their job and are not harmful to humans.

“I don’t know that it’s really about the science,” said Dianna Bourassa, a microbiologist specializing in poultry at Auburn University. “In my microbiological opinion, there are no health implications.”

From the perspective of European farmers, though, whether the health risks are genuine is besides the point. So long as European voters oppose chemical-treated chicken and hormone-treated beef, Europe’s farmers cannot use those farming techniques.

“When you speak to our farmers, it’s about fairness,” explained Pieter Verhelst, a member of the executive board of a Belgian farmers’ union, Boerenbond. “The policy framework we start with is totally different, and those issues are mostly totally out of the hands of farmers.”

And European consumers do seem to support E.U. food and farming rules.

Farmer protests last year loudly opposed more beef imports from South American countries, in part over concerns that the cows might be raised with a growth hormone. An Obama-era trade deal died in part thanks to popular anger over “chlorine chicken” (“Chlorhünchen,” to derisive Germans.)

E.U. public opinion polling has suggested that policies that promote farming and farmers are very popular. In a 2020 poll fielded in-person across the bloc, nearly 90 percent of Europeans agreed with the idea that agricultural imports “should only enter the E.U. if their production has complied with the E.U.’s environmental and animal welfare standards.”

In Europe, including at Mr. Dierendonck’s butchery and farm, there’s a value placed on the old-fashioned, small-scale way of doing things, policymakers and farmers agreed. Mr. Dierendonck does buy some American beef for customers who ask for it — it’s easy to cook, he said — but it’s a small part of the business.

“I like American beef very much, but I don’t like it too much,” said Mr. Dierendonck, explaining that to him, the beef his European suppliers provide is varied, like a fine wine. “For me, it’s about keeping traditions alive.”