UK pledges to provide more assistance to Kyiv

British Prime Minister Boris Johnson pledged on Saturday to provide more economic and military assistance to Kyiv after meeting with Ukrainian President Volodymyr Zelensky.

Johnson pledged 120 armored vehicles and new anti-ship missile systems as well as an additional $500 million in the World Bank lending to Ukraine, according to a Downing Street statement.

At a news conference after their talks, Zelensky said he informed Johnson about the progress of Ukraine's peace talks with Russia and expects London to play a "key role" in providing "security guarantees" for Ukraine.

While several other leaders have visited Ukraine in recent weeks, the meeting between Zelensky and Austrian Chancellor Karl Nehammer, also on Saturday, was significant given Austria's neutral status, which is enshrined in its Constitution.

After the meeting, Nehammer said he expects more EU sanctions against Russia, even as he defended his country's opposition to cutting off deliveries of Russian natural gas.

Meanwhile, Russia and Ukraine conducted their third prisoner exchange on Saturday involving dozens of personnel from both sides.

Ukrainian Deputy Prime Minister Iryna Vereshchuk said 12 Ukrainian soldiers and 14 civilians, including nine women, were returning home under the exchange.

Russian human rights commissioner Tatiana Moskalkova said 14 Russian sailors were returning home on Saturday. "Thanks to the coordinated actions of Russian military staff, 14 sailors from the Azov Concord civilian vessel have been released and are being evacuated to a safe space," Moskalkova said.

She claimed that since the start of Russia's "special military operation" on Feb 24, Ukraine had been "holding the crew of the ship in the port of Mariupol, where the exit to the sea was mined". Mariupol, a key port on the Azov Sea, has suffered widespread destruction and a high death toll since the conflict began.

Two other exchanges of soldiers and civilians have taken place during the conflict.

Fresh satellite images released on Sunday by US private space technology company Maxar Technologies show a 13-kilometer military convoy moving south through the eastern Ukraine town of Velkyi Burluk. The town sits to the east of Kharkiv, close to Ukraine's border with Russia.

Ukrainian officials said major fighting is underway in the east of the country, with heavy shelling reported throughout the Donbass region, ahead of what they are warning may be a major Russian offensive.

Russian President Vladimir Putin has appointed Army General Alexander Dvornikov, 60, as the new general to direct the military operation in Ukraine. The commander of Russia's Southern Military District, he was the first commander of Russia's military operations in Syria in 2015.

NATO Secretary-General Jens Stoltenberg said the bloc is working on plans for a permanent military presence on its borders with Russia.

In the meantime, European Union countries sharing borders with Russia and Belarus barred some cargo vehicles registered in the two countries from entering starting on Friday due to sanctions, the Russian customs service said on Saturday.

Agencies contributed to the story.