Updated: 12.45pm
US president Joe Biden has made an unannounced visit to the Ukrainian capital Kyiv and met Ukrainian president Volodymyr Zelenskiy, days before the first anniversary of Russia's full-scale invasion of Ukraine.
Air raid sirens blared across the Ukrainian capital as Mr Biden visited Kyiv on Monday, but there were no reports of Russian missile or air strikes.
Mr Biden said Washington would stand with Ukraine as long as it takes.
"Your visit is an extremely important sign of support for all Ukrainians," Mr Zelenskiy said.
Mr Biden's visit comes a day before Russian president Vladimir Putin is due to make a major address, expected to set out Russia's aims for the second year of the invasion he launched on February 24th, 2022.
The anniversary has taken on more than symbolic significance, becoming what the West views as motivation for the war's deadliest phase as Moscow hurls thousands of conscripts and mercenaries into a winter offensive.
Russia has secured only scant gains so far in assaults in frozen trenches up and down the eastern front in recent weeks. Kyiv and the West see it as a push to give Mr Putin victories to tout a year after he launched Europe's biggest war since World War Two.
Military aid
During his first, Mr Biden promised new military aid for Ukraine worth $500 million and said additional sanctions would be announced this week against the Russian elite and companies trying to evade sanctions to "back the Russian war machine".
The military aid package will include artillery ammunition, anti-armour systems, and air surveillance radars "to help protect the Ukrainian people from aerial bombardments," he said.
"The cost that Ukraine has had to pay is extraordinarily high. Sacrifices have been far too great," Mr Biden told reporters in Kyiv.
The US president appeared to make no mention of fighter jets, which Ukraine has been seeking from Western allies to help it push back Russian forces.
The United States has been by far the largest supplier of military assistance to help Ukraine repel the better-equipped Russians. -Reuters
