The Kremlin said on Wednesday that President Vladimir Putin accepted some U.S. proposals aimed at ending the war in Ukraine and rejected others but that Russia was ready to meet U.S. negotiators as many times as it took to reach an agreement.

Kremlin spokesman Dmitry Peskov was speaking after talks in Moscow between Putin and U.S. President Donald Trump's special envoy, Steve Witkoff, and son-in-law Jared Kushner went into the early hours of Wednesday morning, with a Kremlin aide saying afterwards that "compromises have not yet been found."

Asked if it would be correct to say that Putin had rejected the U.S. proposals, Peskov said that it would not.

"A direct exchange of views took place yesterday for the first time," Peskov said. "Some things were accepted, some things were marked as unacceptable - this is a normal working process of finding a compromise."

Peskov said that Russia was grateful to Trump for his efforts but that the Kremlin would not be giving a running commentary on discussions with the United States as publicity was unlikely to be constructive.

"Work is currently being carried out at a working expert level," Peskov said. "It is at the expert level that certain results should be achieved that will then become the basis for contacts at the highest level."

A leaked set of 28 U.S. draft peace proposals emerged in November, alarming Ukrainian and European officials who said they bowed to Moscow's main demands.

European powers then came up with a counter-proposal, and at talks in Geneva, the U.S. and Ukraine said they had created an "updated and refined peace framework" to end the war.

Putin on Tuesday said European powers were trying to sink the peace talks by proposing ideas which were absolutely unacceptable to Russia.

Putin's foreign policy aide, Yuri Ushakov, told reporters after the Witkoff talks that Moscow had previously received a 27-point set of proposals and then four additional documents which were discussed with Witkoff.

Putin last week said that the U.S. and Ukraine had divided up the initial proposals into four components. The exact contents have not been disclosed.