Russian forces continued shelling targets in eastern Ukraine on Sunday, as Washington said it would meet Kyiv's request for more military aid by providing "the weapons it needs" to defend itself against Russia.

Russia has failed to take any major cities since it launched its invasion on Feb. 24, but Ukraine says it has been gathering its forces in the east for a major assault and has urged people to flee.

Russian forces fired rockets into Ukraine's Luhansk and Dnipropetrovsk regions on Sunday, officials said. Missiles completely destroyed the airport in the city of Dnipro, said Valentyn Reznichenko, governor of the central Dnipropetrovsk region.

Russia's defence ministry said that high-precision missiles had destroyed the headquarters of Ukraine's Dnipro battalion in the town of Zvonetsky.

Reuters could not immediately confirm the reports.

Since Russia invaded, Zelenskiy has appealed to Western powers to provide more defence help, and to punish Moscow with tough sanctions.

U.S. national security adviser Jake Sullivan told ABC News: "We're going to get Ukraine the weapons it needs to beat back the Russians to stop them from taking more cities and towns."

In extracts from an interview with CBS's "60 Minutes" Zelensky said he had confidence in his own armed forces but "unfortunately I don't have the confidence that we will be receiving everything we need" from the United States.

Zelensky said earlier on Twitter he had spoken on the phone with German Chancellor Olaf Scholz about additional sanctions, as well as more defence and financial support for his country. Zelenskiy also discussed with Ukrainian officials Kyiv's proposals for a new package of EU sanctions, his office said.

Austrian Chancellor Karl Nehammer, who met Zelenskiy in Kyiv on Saturday, will travel to Russia to meet Russian President Vladimir Putin on Monday, the Austrian government said. He will be the first European Union leader to have a face-to-face meeting with Putin since the invasion.

In a video address late on Saturday, Zelenskiy renewed his appeal for a total ban on Russian energy products and more weapons for Ukraine.

The EU on Friday banned Russian coal imports among other products, but has yet to touch oil and gas imports from Russia.

NEW SANCTIONS

Mounting civilian casualties have triggered widespread international condemnation and new sanctions.

A grave with at least two civilian bodies has been found in Buzova village near Kyiv, said Taras Didych, head of the Dmytrivka community that includes Buzova, the latest such reported discovery since Russian forces withdrew from areas north of the capital to focus on the east of the country.

Sullivan said on Sunday he expected Russia's newly appointed general overseeing Ukraine, Aleksandr Dvornikov, to authorise more brutality against the Ukrainian civilian population. He did not cite any evidence

Moscow has rejected accusations of war crimes by Ukraine and Western countries.

Moscow has repeatedly denied targeting civilians in what it calls a "special operation" to demilitarise and "denazify" its southern neighbour. Ukraine and Western nations have dismissed this as a baseless pretext for war.

Russia's invasion has forced about a quarter of Ukraine's 44 million people from their homes, turned cities into rubble and killed or injured thousands.

HEAVY SHELLING

Some cities in the east were under heavy shelling, with tens of thousands of people unable to evacuate.

Calls by Ukrainian officials for civilians to flee gained more urgency after a missile strike hit a train station on Friday in the city of Kramatorsk, in the Donetsk region, that was full of people trying to leave.

Ukrainian officials said more than 50 people were killed. Russia has denied responsibility, saying the missiles used in the attack were only used by Ukraine's military.

Reuters was unable to verify the details of attack.

Residents of the region of Luhansk would have nine trains on Sunday to get out on, the region's governor, Serhiy Gaidai, wrote on the Telegram message service.

In a Palm Sunday homily, Pope Francis called for an Easter truce in Ukraine and, in an apparent reference to Russia, questioned the value of planting a victory flag "on a heap of rubble”

At a sermon in Moscow, Patriarch Kirill, the head of Russia's Orthodox Church and a close ally of President Vladimir Putin, called on people to rally around the authorities.