ZAPORIZHZHIA, Ukraine, April 24 (AFP) - Kyiv prepared on Saturday (Apr 23) for its first wartime visit from two top United States officials, as Ukraine accused Russia of killing eight people in a strike on Odesa that all but buried hopes of a truce for Orthodox Easter.

The Sunday visit by Secretary of State Antony Blinken and Defense Secretary Lloyd Austin will come at a symbolic moment - on the day the war enters its third month - and with fierce battles continuing in the country's east.

It also comes as the situation in the shattered port city of Mariupol remains bleak. The latest of many attempts to evacuate civilians failed on Saturday, and the situation facing an embattled unit of Ukrainian fighters sheltering in tunnels under a sprawling steel mill there appeared increasingly desperate.

A number of European leaders have already travelled to Kyiv to meet with President Volodymyr Zelenskyy and underscore their support, but the United States - a leading donor of finances and weaponry - had yet to send any top officials.

Asked by AFP to comment on the highly sensitive trip by two of President Joe Biden's top Cabinet members, the State Department declined.

Zelenskyy, who announced the visit, also issued a new call for a meeting with Russian counterpart Vladimir Putin "to end the war".

"I think that whoever started this war will be able to end it," Zelenskyy said, adding that he was "not afraid" to meet the Russian leader.

But he again stressed that Kyiv would abandon talks with Moscow if its troops in Mariupol were killed.

Zelenskyy also criticised a decision by United Nations Secretary-General Antonio Guterres to visit Moscow on Tuesday, before heading to Kyiv.

"There is no justice and no logic in this order," he said.

Around 200 residents gathered at a designated evacuation point in Mariupol on Saturday but were "dispersed" by Russian forces, city official Petro Andryushchenko said on Telegram, adding: "The evacuation was thwarted."

He claimed that others had been told to board buses headed to places controlled by Russia.

Mariupol, which the Kremlin claims to have "liberated", is pivotal to Russia's war plans to forge a land bridge to Russian-occupied Crimea - and possibly beyond as far as Moldova.

Ukraine says that hundreds of its forces and civilians are holed up inside the Mariupol steel plant. Kyiv has repeatedly called for a ceasefire to allow civilians - many barely surviving with little or no access to food or water - to exit safely.

But on Saturday, a Ukrainian presidential adviser, Oleksiy Arestovich, said that Russian forces had resumed air strikes on the factory.

"Our defenders hold on regardless of the very difficult situation and even carry out counter-raids," he said.