NATO defense chiefs were due to hold a virtual meeting Wednesday, a senior alliance official said, as Western countries pushing for an end to Russia's war on Ukraine devise possible future security guarantees for Kyiv that could help forge a peace agreement.

Italian Admiral Giuseppe Cavo Dragone, the chair of NATO's Military Committee, said that 32 defense chiefs from across the alliance would hold a video conference as a U.S.-led diplomatic push seeks to end the fighting.

Russian Foreign Minister Sergei Lavrov warned on Wednesday that discussing any Western security guarantees for Ukraine without Russian involvement was a "road to nowhere".

"The West understands perfectly well that seriously discussing security guarantees without the Russian Federation is a utopia, a road to nowhere," Lavrov told reporters.

Kyiv said Tuesday that Russia had returned the bodies of one thousand killed Ukrainian soldiers, as part of previous agreements brokered between the two warring countries.

"Unfortunately, among those repatriated are the bodies of five Ukrainian servicemen who died in captivity," the government agency coordinating the repatriation announced on social media, adding that it would carry out tests to identify the remains delivered from eastern Ukraine and the Kursk region of Russia.

Russian Foreign Minister Sergei Lavrov said on Tuesday any peace deal on Ukraine must ensure Russia's security, speaking a day after high-level talks in Washington to resolve to conflict.

"Without respect for Russia's security interests, without full respect for the rights of Russians and Russian-speaking people who live in Ukraine, there can be no talk of any long-term agreements," Lavrov told state TV channel Rossiya 24.

Ukraine's allies were meeting on Tuesday to discuss the outcome of fast-moving talks to end the war with Russia, after indications that Volodymyr Zelensky could sit down with Vladimir Putin for a peace summit.

Hopes of a breakthrough rose when the Ukrainian president and European leaders met US President Donald Trump in Washington on Monday, who said he had also spoken by phone with his Russian counterpart.

President Donald Trump said he's begun arrangements for a face-to-face meeting between Vladimir Putin and Volodymyr Zelensky to discuss a pathway to end Russia's invasion of Ukraine, while affirming that the U.S. would back European security guarantees aimed at preventing Moscow from reinvading its neighbor once the current conflict ends.

Details of the security guarantees and Trump's efforts to arrange peace talks were still evolving as an extended meeting among Trump, Zelensky and other European leaders wrapped up at the White House.

French President Emmanuel Macron said Monday that White House talks involving Ukrainian President Volodymyr Zelensky did not raise Kyiv surrendering territory, despite U.S. leader Donald Trump's public calls for compromise.

Asked by reporters if Trump had said that concessions were necessary before any U.S. security guarantees to Ukraine, Macron said, "No, that wasn't discussed at all. We're well away from that."

China said on Tuesday it supports "all efforts" towards peace between Russia and Ukraine after presidents Vladimir Putin and Volodymyr Zelensky looked set for a summit in the coming weeks.

"China always believes that dialogue and negotiation are the only solution to the Ukraine crisis," foreign ministry spokeswoman Mao Ning said, adding: "We support all efforts that are conducive to peace."

U.S. President Donald Trump said reclaiming Crimea or entering NATO were off the table for Ukraine, as President Volodymyr Zelensky arrived in Washington for Monday talks aimed at ending the war with Russia.

Here are the outcomes of a summit meeting on Ukraine between U.S. President Donald Trump and Russian President Vladimir Putin, based on statements from Saturday: