U.S. President Biden visits Kyiv
Ukraine's President Volodymyr Zelenskiy and U.S. President Joe Biden shake hands before a meeting, amid Russia's attack on Ukraine, in Kyiv, Ukraine February 20, 2023. Ukrainian Presidential Press Service/Handout via REUTERS Reuters

U.S. President Joe Biden made an unannounced visit to Ukraine on Monday, a major show of support ahead of the one-year anniversary of Russia's invasion which has seen Moscow launch a massive assault across frontlines in the east.

Air raid sirens blared across the Ukrainian capital as Biden visited Kyiv, but there were no reports of Russian missile or air strikes.

President Volodymyr Zelenksiy said he and Biden discussed long range weapons during the visit. The White House said Biden would announce more sanctions on Russia and military support for Ukraine.

Biden arrived in the Ukrainian capital a day before President Vladimir Putin was due to make a major address, expected to set out Russia's aims for the second year of the invasion he launched on Feb 24 last year.

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 Putin victories to tout a year after he launched Europe's biggest war since World War Two.

(Writing by Peter Graff;Editing by Andrew Cawthorne)

A general view shows an apartment building damaged by a Russian military strike in the frontline city of Bakhmut
A general view shows an apartment building damaged by a Russian military strike, amid Russia's attack on Ukraine, in the frontline city of Bakhmut in Donetsk region, Ukraine February 19, 2023. Reuters
People stand by a coffee stall at dusk during power shortage in Mykolaiv
People stand by a coffee stall at dusk, during a power shortage, amid Russia's invasion of Ukraine, in Mykolaiv, Ukraine, February 19, 2023. Reuters
Aftermath of recent shelling in Donetsk
Smoke rises above a building of the prosecutor's office damaged in shelling in the course of Russia-Ukraine conflict in Donetsk, Russian-controlled Ukraine, February 19, 2023. Reuters
Local residents walk on an empty street in Bakhmut
Local residents walk on an empty street, as Russia's attack on Ukraine continues, in the frontline city of Bakhmut, Ukraine February 19, 2023. Reuters