Russian forces called in airstrikes on a besieged steel factory in the southern city of Mariupol to try to dislodge the last Ukrainian troops holding out in the strategic port, Ukrainian officials said Sunday, while President Volodymyr Zelenskyy said he would meet in Kyiv with two top American officials.

Zelenskyy gave few details about the logistics of his talks with U.S. Secretary of State Antony Blinken and U.S. Defense Secretary Lloyd Austin on what was the 60th day since Russia invaded Ukraine. But he told reporters he expected results — "not just presents or some kind of cakes, we are expecting specific things and specific weapons."

The visit would be the first to Kyiv by high-level U.S. officials since the invasion began Feb. 24. While visiting Poland in March, Blinken stepped briefly onto Ukrainian soil to meet with the country’s foreign minister. Zelenskyy’s last face-to-face meeting with a U.S. leader was Feb. 19 in Munich with Vice President Kamala Harris.

The meeting was set to take place as Ukrainians and Russians observed Orthodox Easter, an occasion Zelenskyy highlighted the allegorical significance of during his nightly address to his country's people after nearly two months of war.

"There will be a Resurrection. Life will defeat death. The truth will defeat any lies. And evil will be punished," he said. "And Russia will have to learn these truths again, it’s only a matter of time."

Russia has been trying to take Mariupol for nearly two months, and the city on the Sea of Azov has seen some of the war's worst deprivations. Its capture would deprive Ukraine of a vital port, free up Russian troops to fight elsewhere, and establish a land corridor to the Crimean Peninsula, which Moscow seized in 2014.

Some 2,000 troops have been fighting tenaciously to hold on to the last remaining Ukrainian outpost in the city, the Azovstal steel plant, which also has civilians taking refuge in its labyrinthine tunnel system.

Russian forces have continued to pummel the plant, hitting it with air strikes, including by long-range aircraft, Oleksandr Shtupun, spokesman for the Ukrainian Armed Forces General Staff, said Sunday.

Mariupol has been blockaded for most of the war. Ukrainian officials have said they expect to find thousands of dead civilians and evidence of war crimes there when the fighting ends. Satellite images have shown what appear to be mass graves dug in towns to the west and east of Mariupol.

In the last day, Russia also pressed its attacks elsewhere in the eastern Donbass region, where Moscow-backed separatists controlled some territory before the war and the Russians are aiming to gain full control over Ukraine’s eastern industrial heartland.

Shtupun said Russian forces intensified their assault operations toward the cities of Popasna and Siverodonetsk in Luhansk, and Kurakhiv in Donetsk. Luhansk regional Gov. Serhiy Haidai said Sunday that eight people were killed and two others were wounded in a Russian barrage on Saturday.

The Russians also have shelled the Dnipro region west of Donbass, where at least one person was killed by a Russian missile, according to regional Gov. Valentyn Reznichenko.

Russia has pulled back forces from Ukraine's capital, Kyiv, and the north of the country to feed into the Donbass offensive, but the British Ministry of Defense said Sunday that Ukrainian forces had repelled numerous assaults in the past week.

"Despite Russia making some territorial gains, Ukrainian resistance has been strong across all axes and inflicted significant cost on Russian forces," the ministry said in an intelligence update.

"Poor Russian morale and limited time to reconstitute, re-equip and reorganize forces from prior offensives are likely hindering Russian combat effectiveness," it said.

The Ukrainian military said Saturday it destroyed a Russian command post in Kherson, a southern city that fell to Russian forces early in the war.

The command post was hit on Friday, killing two generals and critically wounding another, the Ukrainian military intelligence agency said in a statement. The Russian military did not comment on the claim, which could not be confirmed.

If true, at least nine Russian generals have been killed since the start of the invasion, according to Ukrainian reports.

On Saturday the Azov Regiment of Ukraine’s National Guard, which has members holed up in the Mariupol steel plant, released a video of around two dozen women and children sheltering there. Its contents could not be independently verified, but if authentic, it would be the first video testimony of what life has been like for civilians trapped underground there.

The video shows soldiers giving sweets to children who respond with fist-bumps. One young girl said she and her relatives had "seen neither the sky nor the sun" since they left home Feb. 27.

The regiment’s deputy commander, Sviatoslav Palamar, told the AP the video was shot Thursday. The Azov Regiment has its roots in the Azov Battalion, which was formed by far-right activists in 2014 at the start of the separatist conflict in eastern Ukraine and has elicited criticism for some of its tactics.

More than 100,000 people — down from a prewar population of about 430,000 — are believed to remain in Mariupol with scant food, water or heat. Ukrainian authorities estimate that over 20,000 civilians have been killed in the city.

Yet another attempt to evacuate women, children and older adults from Mariupol failed Saturday. Petro Andryushchenko, an adviser to Mariupol’s mayor, said Russian forces did not allow Ukrainian-organized buses to take residents to Zaporizhzhia, a city 227 kilometers (141 miles) to the northwest.