Making the first official US visit to Ukraine since Russia invaded two months ago, Washington's top diplomat and its defense secretary pledged additional military aid, including advanced weapons, and a return of US envoys to Kyiv.
Secretary of State Antony Blinken and Secretary of Defense Lloyd Austin met Ukrainian President Volodomyr Zelenskiy and other top officials in Kyiv late on Sunday, having travelled overland from Poland in a visit designed to show Western support.
US officials said the cabinet secretaries pledged new assistance worth $713 million for Zelenskiy's government and other countries in the region that are fearful of further Russian aggression.
"We are inspired by the resilience of Orthodox Christians in Ukraine in the face of President Putin's brutal war of aggression," Blinken said earlier on Twitter, as fighting in the east overshadowed religious celebrations for the Orthodox Easter.
The high level US visit highlighted the shift in the conflict since Ukrainian forces, armed with a massive influx of weapons from the West, fought off a Russian assault on the capital Kyiv, Reuters reported.
Russia has failed to capture any major city since the invasion started on Feb. 24, and having failed to take Kyiv, Russia has concentrated its forces in the south and east, where it has launched an offensive that Zelenskiy dubbed the battle of the Donbas.
Before meeting the US delegation, Zelenskiy on Twitter thanked US President Joe Biden and the United States for leadership in supporting Ukraine.
Earlier, in an emotional address at Kyiv's 1,000-year-old Saint Sophia Cathedral to mark the Orthodox Easter, Zelenskiy said his nation would overcome "dark times".
US diplomats will return to Ukraine in coming weeks, with Washington announcing a new ambassador.
"There's no substitute for that face-to-face engagement, and of course there is a symbolism to being back in the country," said a State Department official, who briefed reporters in Poland on condition of anonymity.
With a semblance of normal life returning to the capital, several countries have reopened embassies in recent days and some residents who fled the fighting returned for Easter.