US President Joe Biden has pledged to provide Ukraine with five new strategic air defence systems to counter relentless Russian attacks, in a forceful speech welcoming Nato leaders to Washington DC, Ednews reports via BBC.

In brief but strongly delivered remarks at the opening of the summit, the president declared the military alliance "more powerful than ever" as it faced a "pivotal moment" in the war between Russia and Ukraine.

Mr Biden said the US would partner with Germany, Italy, the Netherlands and Romania to donate Patriot missile batteries and other systems to aid Ukraine, amid growing civilian casualties in the conflict.

The announcement comes just two days after a Russian missile levelled a children's hospital in the Ukrainian capital Kyiv - an attack the city's mayor said was among the worst since the beginning of the war.

Some 43 people were killed by blasts across the country in Monday's attack, with over a hundred more injured, officials said. Russia denied responsibility for the attack, but the UN - and analysts who spoke to BBC Verify - pinned the blame on Moscow.

President Volodymyr Zelensky has spent months pleading with his Western allies to step up supplies of air defences.

In total, Nato plans to donate five strategic air defence systems and dozens of smaller, strategic anti-air batteries over the coming year.

"The war will end with Ukraine remaining a free and independent country," Mr Biden said on Tuesday afternoon. "Russia will not prevail. Ukraine will prevail."

President Biden spoke for about 13 minutes in a clear voice, a marked difference from his fumbling tone during last month's presidential debate with Trump.