President Vladimir Putin still supports the idea of a ceasefire in Ukraine, but Russia has not yet been given answers to key questions it has about a truce proposed by the administration of U.S. President Donald Trump, the Kremlin said Monday.

Trump, who says he wants to be remembered as a peacemaker, has repeatedly said he wants the three-year conflict in Ukraine to end and has warned of the risks of it escalating into a world war between the United States and Russia.

Putin said last month that Russia supported a U.S. proposal for a ceasefire in Ukraine in principle, but that fighting could not be paused until a number of crucial conditions
were worked out or clarified.

The Kremlin said those questions had not yet been answered.

"President Putin does support the idea of the need for a ceasefire, but before that a number of questions must be answered," Kremlin spokesman Dmitry Peskov told reporters.

"These questions are still hanging in the air; so far no one has given an answer to them."

Putin has said that any peace agreement must address what Moscow sees as the root causes of the conflict: essentially a tug of war between Russia and the West over Ukraine's future and the post-Soviet enlargement of NATO towards Russia's borders.

Putin has said the ceasefire would have to ensure that Ukraine did not simply use it to regroup, and that key questions about verification of a truce would need to be clarified.

The Kremlin on Monday laid the blame for the lack of answers on Kyiv which it said was unable to control a number of its "extremist and nationalist units."

Ukrainian President Volodymyr Zelenskiy has said in turn that Putin's conditions for a ceasefire are unrealistic and has accused the Russian leader of wanting to continue the war.