Russia says it wants guarantees that NATO will not grant Ukraine membership in any peace deal.
Deputy foreign minister Alexander Grushko told Russian media outlet Izvestia: “We will demand that ironclad security guarantees become part of this agreement.
“Part of these guarantees should be the neutral status of Ukraine, the refusal of Nato countries to accept it into the alliance.”
US President Donald Trump is expected to speak to Mr Putin on Tuesday as talks continue to bring an end to the fighting.
Mr Trump said on Sunday evening: “A lot of work’s been done over the weekend. We want to see if we can bring that war to an end.”
“We will be talking about land. We will be talking about power plants.”
He added there were discussions over “dividing up certain assets” between Russia and Ukraine.
Ukraine agreed to a US-proposed 30-day ceasefire last week.
The Russian president said he supports a ceasefire but said several details needed to be negotiated.
Prime Minister Sir Keir Starmer on Saturday said a group of nations – known as the “coalition of the willing” – to support Ukraine is moving into an “operational phase”.
Military chiefs from the countries will meet in London this week to discuss peacekeeping plans in Ukraine.
Dmitry Medvedev, deputy chairman of the Security Council of Russia, hit out at the plans which are being spearheaded by the UK and France.
He wrote on X: “Macron and Starmer are playing dumb. Time and again they are told that peacekeepers must be from non-NATO states.”