Russian and Ukrainian officials gave their most upbeat assessments yet on Sunday of progress in their talks on the war in Ukraine, suggesting there could be positive results within days.
Separately, US Deputy Secretary of State Wendy Sherman said Russia was showing signs of willingness to engage in substantive negotiations about ending a conflict in which thousands have died. More than 2.5 million people have fled.
Ukraine has said it is willing to negotiate, but not to surrender or accept any ultimatums.
"We will not concede in principle on any positions. Russia now understands this. Russia is already beginning to talk constructively," Ukrainian negotiator and presidential adviser Mykhailo Podolyak said in a video posted online.
"I think that we will achieve some results literally in a matter of days," he said.
Also read: Putin sees some 'positive shifts' in Russia-Ukraine talks
RIA news agency quoted a Russian delegate, Leonid Slutsky, as saying the talks had made substantial progress.
"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.
Neither side indicated what the scope of any agreement might be.
Their public comments were issued almost at the same time. They 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.
In a tweet, Podolyak said Russia was carefully listening to Ukraine's proposals. "Our demands are – the end of the war and the withdrawal of (Russian) troops. I see the understanding and there is a dialogue," he said.
Last Monday, the Kremlin's chief spokesperson said Russia was ready to halt military operations "in a moment" if Kyiv met a list of conditions.
Also read: Russia will stop 'in a moment' if Ukraine meets terms: Kremlin
Among the demands were for Ukraine to acknowledge Crimea as Russian territory, and recognise the separatist republics of Donetsk and Lugansk as independent states.
Ukrainian President Volodymyr Zelenskiy told ABC last week that "we can discuss and find a compromise on how these territories will live on" while adding "we're not ready for capitulation".
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".
Talks between the Russian and Ukrainian foreign ministers produced no apparent progress towards a ceasefire last Thursday but analysts said the fact they were even meeting left a window open for ending the war.