Prime Minister Viktor Orban of Hungary met with President Vladimir V. Putin at the Kremlin on Friday, a rare trip to Russia by a Western leader and one that quickly stirred discord in the European Union.

Mr. Orban made the trip three days after visiting President Volodymyr Zelensky of Ukraine in Kyiv, the Ukrainian capital. And it was the same week that Hungary took over the European Union’s rotating presidency, prompting other European leaders to quickly declare that Mr. Orban was not representing them in Moscow.

A spokesman for Mr. Orban, Zoltan Kovacs, said the Hungarian leader was in Moscow “as part of his peace mission.”

But Mr. Putin, in his televised comments to Mr. Orban at the beginning of their meeting, signaled he was not budging from the sweeping demands he made of Ukraine last month. At the time, Mr. Putin said Russia would be ready for a cease-fire only if Ukraine withdrew troops from the four regions that Moscow has claimed as its own and dropped its aspirations to join NATO.

“Our positions on the possibility of a peace settlement are described there,” Mr. Putin told Mr. Orban, referring to those demands. “I am, of course, ready to discuss and tell you about various nuances.”

Mr. Orban, long an object of European chagrin for his embrace of far-right politics and of authoritarians like Mr. Putin, has said he wants to promote peace negotiations between Russia and Ukraine. Ukrainian leaders have rejected talks with Russia because they say that Mr. Putin would only seek their country’s capitulation.

It was the first time that a European Union leader had visited Russia for an official meeting with Mr. Putin since the first months of the Ukraine invasion. The Austrian chancellor, Karl Nehammer, made the trip in April 2022.

It was Mr. Orban’s second meeting with Mr. Putin since Russia invaded Ukraine in February 2022. He last met the Russian leader in October in Beijing, telling him that Hungary “never wanted to confront Russia” and “has always been eager to expand contacts.”

Mr. Orban, who has won four elections in a row by casting his domestic rivals as traitors and warmongers beholden to Brussels, delights in defying his nominal allies in the European Union and NATO, which will be holding a summit meeting in Washington next week.

He presents himself as a maverick in the mold of former President Donald J. Trump, a go-it-alone defender of national interests heedless of establishment opinion.

“I am very thankful,” Mr. Orban told Mr. Putin on Friday, according to a Russian translation of his televised remarks, “that you agreed to receive me, even in such difficult conditions.”

His trip to Moscow in defiance of the European Union’s policy of shunning Mr. Putin fits into a long pattern of Hungarian disdain for Europe’s fitful efforts to forge a joint foreign policy.

In recent months, Mr. Orban’s foreign minister, Peter Szijjarto, has repeatedly reached out to autocratic nations kept at arm’s length by Brussels. He has traveled to Belarus, which has been slapped with punishing European sanctions, and Iran, which also has frosty relations with Europe and is also under sanctions.

Mr. Szjijjarto on Friday posted a photograph of himself on a red carpet at an airport in Moscow in front of a Hungarian Air Force plane. “Arriving in Moscow. Another step for peace!” he said.

Other than vague public remarks calling for a “time-bounded cease-fire” during his visit on Tuesday to Kyiv, Mr. Orban has shed no light on how he envisages possible peace in Ukraine.

Mr. Orban’s trip was doubly provocative because Hungary this week took over the European Union’s rotating presidency, a largely clerical role with little real power but one that puts the country holding the six-month position in the spotlight.

Chancellor Olaf Scholz of Germany said that he had not known about Mr. Orban’s trip in advance and noted that he was not representing the European Union.

Josep Borrell Fontelles, the bloc’s top diplomat, issued a statement saying that Mr. Orban’s “visit to Moscow takes place, exclusively, in the framework of the bilateral relations between Hungary and Russia.”

The Hungarian prime minister is “thus not representing” the European Union “in any form,” Mr. Borrell added.

As word spread on Thursday about Mr. Orban’s quietly planned trip — it was not announced until after his plane landed in Moscow on Friday — other European Union officials were quick to condemn it.

“The EU rotating presidency has no mandate to engage with Russia on behalf of the EU,” said Charles Michel, president of the European Council, the body representing the heads of government of the member states.

“The European Council is clear: Russia is the aggressor, Ukraine is the victim,” Mr. Michel said, writing on social media. “No discussions about Ukraine can take place without Ukraine.”

Prime Minister Donald Tusk of Poland addressed a social media post directly to Mr. Orban. “The rumours about your visit to Moscow cannot be true,” Mr. Tusk wrote, “or can they?”

Poland’s previous governing party, Law and Justice, a nationalist force that for years stood shoulder-to-shoulder with Mr. Orban in his battles with Brussels over immigration and other issues, has also been dismayed by Hungary’s outreach to the Kremlin.

In an interview on Thursday, Poland’s former conservative prime minister, Mateusz Morawiecki, voiced alarm at Mr. Orban’s friendly policy toward Russia and what he described as Hungary’s “peace mantra.”

This, he said had made Law and Justice reluctant to join a new Hungarian-led alliance in the European Parliament called Patriots for Europe, despite shared views on many other issues.

“Ukraine is a Rubicon, a kind of red line for us,” Mr. Morawiecki said. “Russia must not win this war.”

Mr. Morawiecki, who traveled to Kyiv to show support just days after the Russian invasion, said he was encouraged by Mr. Orban’s belated visit to Ukraine this week as a sign that the Hungarian leader was moderating his previous hostility to President Zelensky. Poland, he said, shares Hungary’s desire for a peace settlement but not one based on Ukrainian defeat.

“Who doesn’t want peace?” he said. “But the quickest way to end a war is to lose it,” he added, insisting that this was not an option anyone wanted for Ukraine except Russia.

Almost all Western leaders have shunned meetings with Mr. Putin since Russia invaded Ukraine, seeking instead to isolate Mr. Putin on the world stage.

Outside the West, however, leaders have not been shy about sitting down with their Russian counterpart: Xi Jinping, China’s leader, met with Mr. Putin this week in Kazakhstan, and Prime Minister Narendra Modi of India is scheduled to visit Moscow next week.

Christopher F. Schuetze and Marc Santora contributed reporting.