Prime Minister Viktor Orban of Hungary, one of the few European leaders who maintains warm relations with Moscow and has called on Kyiv to capitulate to Russia’s demands to end the bloodshed, arrived in Ukraine on Tuesday morning for his first wartime visit to the nation, his spokesman said.

A vocal critic of supplying military and other financial assistance to Ukraine who relishes his role as the odd man out in both the European Union and NATO, Mr. Orban said in an interview with the Hungarian news media on Monday night that the visit would be “the first steps” in promoting his vision for ending the war.

That vision stands in stark contrast to the plan outlined by President Volodymyr Zelensky of Ukraine, whose government has consistently said that Russia must pull its troops out of Ukraine’s internationally recognized territory before any peace talks can begin. President Vladimir V. Putin of Russia, however, has shown no signs of backing down, leaving the two sides as far apart as ever.

“He is trying to break out of political no man’s land in the E.U., and showing a more open approach toward Kyiv would be key in this regard,” Edit Zgut-Przybylska, an assistant professor at the Polish Academy of Sciences who has written extensively about Russian influence in Hungary, said of Mr. Orban.

Although Hungary recently took over the rotating presidency of the European Union, she said, he will not be able to “occupy Brussels” as he has vowed, and therefore must find a different tactic to exert his influence.

Despite Mr. Orban’s open embrace of Moscow — including a meeting with Mr. Putin in Beijing, where he told the Russian leader that Hungary “never wanted to confront Russia” and “has always been eager to expand contacts” — Mr. Zelensky said it was important that Ukraine’s and Hungary’s leaders hold formal discussions.