A Russian delegate for talks with Ukraine was quoted on Sunday saying they had made significant progress and it was possible the delegations could soon reach draft agreements, although he did not say what the agreements would cover.

RIA news agency quoted Leonid Slutsky as comparing the state of the talks now with the situation when they first started and said there was "substantial progress."

His comments came on day 18 of the war, which began when Russian forces invaded Ukraine on Feb. 24 in what the Kremlin terms a special military operation.

"According to my personal expectations, this progress may grow in the coming days into a joint position of both delegations, into documents for signing," Slutsky said.

It was not clear what the scope of any such documents might be. Ukraine has said it is willing to negotiate but not to surrender or accept any ultimatums.

Three rounds of talks between the two sides in Belarus, most recently last Monday, had focused mainly on humanitarian issues and led to the limited opening of some corridors for civilians to escape fighting.

Russian President Vladimir Putin said on Friday there had been some "positive shifts" in the talks but did not elaborate. On Saturday, the Kremlin said the discussions between Russian and Ukrainian officials had been continuing "in video format."