Ukrainian President Volodymyr Zelenskiy said on Wednesday peace talks were sounding more realistic but more time was needed, as Russian airstrikes killed five people in the capital Kyiv and the refugee tally from Moscow's invasion reached 3 million.

Moscow has not captured any of Ukraine's 10 biggest cities following its incursion that began on Feb 24, the largest assault on a European state since 1945.

Ukrainian officials have raised hopes the war could end sooner than expected, possibly by May, saying Moscow may be coming to terms with its failure to impose a new government by force and running out of fresh troops.

"The meetings continue, and...