US Vice-President Kamala Harris on Friday said Russian President Vladimir Putin "shows no sign of engaging in serious diplomacy" as she accused Moscow of "atrocious and outrageous conduct" in Ukraine.
"The US has been attempting sincerely to engage in diplomacy actively and from everything we know and witnessed Putin shows no sign of engaging in serious diplomacy," Harris said on a visit to Romania.
"We maintain that diplomacy is the way to resolve issues, (but) that coexists with our commitment to ensure that our allies are strong and that there must be serious consequences and accountability for Russia's doings," Harris told a news conference in Bucharest with Romanian President Klaus Iohannis.
"That's why we engaged in historic sanctions," added Harris of the Western response to the February 24 invasion as she warned of "more actions that we will take to ensure serious consequences for what is atrocious and outrageous conduct".
"We are clear that any intentional attack by targeting civilians is a war crime. Period," said Harris, alluding to a midweek attack on a maternity hospital in the Ukrainian port city of Mariupol which killed at least three people, including a child.
The World Health Organization has to date logged 26 attacks, causing at least 12 deaths, on health facilities in Ukraine since the conflict began.
Harris has been visiting NATO allies Poland and Romania this week to show US support as conflict rages over their respective borders with Ukraine.
Washington last month redeployed a 1,000-strong unit US service personnel from Germany to Romania to a base near the Black Sea, all but doubling the US troop presence in the country.
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