WASHINGTON (Reuters) - Hungary sees a potential return of former U.S. President Donald Trump as a "chance for peace" in Ukraine, Foreign Minister Peter Szijjarto said on Wednesday as a NATO summit began with most allies hoping to send a firm message of support for Kyiv.

Hungarian Prime Minister Viktor Orban visited Moscow last week on what he called a peace mission, but the initiative angered some of Budapest's fellow NATO allies, who said the trip handed legitimacy to Russian President Vladimir Putin's claims to Ukrainian territory seized since Russia's 2022 invasion.

The meeting of NATO leaders takes place in Washington as U.S. President Joe Biden is under pressure after a disastrous June 27 debate that boosted Trump in the polls ahead of a Nov. 5 election and raised concerns among allies about how the Republican candidate would approach the alliance and the war in Ukraine.

In an interview with Reuters in Washington, Szijjarto said Hungary's aim was to bring an end to the war through peace talks involving both Russia and Ukraine.

"I think a very strong external impact must take place in order to make them negotiate at least," Szijjarto said. "Who has the chance for that in the upcoming period? That's only President Trump if he is elected."

Orban's recent meetings with both Putin and Ukrainian President Volodymyr Zelenskiy had demonstrated the vast distance separating the two sides, and other Western leaders were unwilling or unable to bring them together, he said.

Trump has said he would quickly end the war. He has not offered a detailed plan to achieve that, but Reuters reported last month that advisers to the former president had presented him with a plan to end the war in part by conditioning any future aid to Kyiv on Ukraine joining peace talks.

"We see a chance for peace if President Trump is winning. We see a chance for good Hungary-U.S. relationships if President Trump is winning," he said.

Hungary's position on Ukraine contrasts to other NATO leaders, including Biden, who say Kyiv must decide when to negotiate an end to the war. Ukraine says it will not give up any territory in a peace deal.

Szijjarto earlier met Ukrainian Foreign Minister Dmytro Kuleba, who said any initiatives to end the war should not be based on Russian narratives, Kuleba said on X.

Szijjarto said Hungary does not see Russia as a threat to NATO or European Union members, saying Russia's leaders are "rational" and would not risk a direct conflict with the West.

Orban's visits to Kyiv, Moscow and Bejing, where he also discussed the war in Ukraine, have been sharply criticized by European Union members who said it gave the impression he was acting on behalf of the bloc. Hungary took over the rotating EU presidency this month.

The U.S. ambassador in Budapest, David Pressman, said last week that Orban's meeting with Putin and Szijjarto's repeated visits to Moscow were damaging to Hungary's relations with its allies.

"This is not about 'peace'; it's about profit," the ambassador said on X.

Szijjarto said the comment was "unacceptable" interference from a diplomat.

"What the U.S. ambassador is doing in Budapest is political activism...He is the leader of the opposition," he said.

NATO allies are expected to sign off on an arms and training package for Ukraine during the summit.

Szijjarto said Hungary was not standing in the way of NATO approving the plan but would not participate in it.

"We see a huge escalatory risk there," he said. "Looking at this war from a couple hours' drive or looking at this war from a perspective of a 10-hour flight. That's a different aspect, believe me," he said, citing the plight of Ukrainian refugees in Hungary as well as ethnic Hungarians inside Ukraine.

(Reporting by Simon Lewis; additional reporting by Anita Komuves; Editing by Angus MacSwan)

By Simon Lewis