Senior Ukrainian officials held a meeting in Istanbul on Friday with U.S. envoy Keith Kellogg and senior aides to the French, British and German leaders, Ukrainian presidential chief of staff Andriy Yermak said on social media.

The meeting was attended from the Ukrainian side by Yermak as well as Foreign Minister Andriy Sybiha and Defence Minister Rustem Umerov.

Russian and Ukrainian negotiators were in Istanbul on Friday for what was billed as their first direct peace talks in more than three years, under pressure from U.S. President Donald Trump to end Europe's deadliest conflict since World War Two.

The encounter anticipated at the Dolmabahce Palace on the Bosphorus would be a sign of diplomatic progress between the warring sides, who had not met face-to-face since March 2022, the month following Russia's invasion.

Expectations for a major breakthrough, already low, were dented further on Thursday when Trump said there would be no movement without a meeting between himself and Russia's President Vladimir Putin.

WATCH | Putin won't attend peace talks; Moscow sending aides and deputy ministers instead: 

Putin skipped peace talks in Turkey that he himself suggested

The Kremlin confirmed early Thursday that Russia President Vladimir Putin would not be attending peace talks in Istanbul, sending aides and deputy ministers instead. Ukrainian President Volodymyr Zelenskyy bowed out soon after, dismissing the Russian delegation as 'decorative.' William Taylor, a former U.S. ambassador to Ukraine, says it's especially odd since Putin suggested the meeting in the first place.

Trump, winding up a Middle East tour and heading back to Washington, said on Friday he would meet the Russian leader "as soon as we can set it up."

In Istanbul, a Reuters reporter saw the first vehicles arriving at the talks venue, including white minibuses and several black cars. A Turkish Foreign Ministry source said a meeting had started between Turkish, U.S. and Ukrainian officials.

Turkish sources had said the Ukrainian and Russian delegations would meet in the presence of Turkish officials, beginning at 0930 GMT (5:30 a.m. ET).

Putin on Sunday proposed direct talks with Ukraine in Turkey, but has spurned a challenge from Ukrainian President Volodymyr Zelenskyy to meet him in person, and instead has sent a team of mid-ranking officials to the talks.

Zelenskiy said Putin's decision not to attend but to send what he called a "decorative" lineup showed the Russian leader was not serious about ending the war. Russia accused Ukraine of trying "to put on a show" around the talks.

U.S. Secretary of State Marco Rubio, who also flew to Istanbul on Friday, told reporters the night before that, based on the level of the negotiating teams, a major breakthrough was unlikely.

"I hope I'm wrong. I hope I'm 100% wrong. I hope tomorrow the news says they've agreed to a ceasefire; they've agreed to enter serious negotiations. But I'm just giving you my assessment, honestly," he said.

Russia says it sees the talks as a continuation of the negotiations that took place in the early weeks of the war in 2022, also in Istanbul.

But the terms under discussion then, when Ukraine was still reeling from Russia's initial invasion, would be deeply disadvantageous to Kyiv. They included a demand by Moscow for large cuts to the size of Ukraine's military.

With Russian forces now in control of close to a fifth of Ukraine, Putin has held fast to his longstanding demands for Kyiv to cede territory, abandon its NATO membership ambitions and become a neutral country.

Ukraine rejects these terms as tantamount to capitulation, and is seeking guarantees of its future security from world powers, especially the United States.