Almost exactly one year after Russia’s invasion, U.S. Vice President Joe Biden paid a surprise visit to Kyiv and pledged $500 million in fresh military assistance for Ukraine.

Biden said this week’s announcement of new measures against the Russian ruling class and businesses trying to circumvent sanctions to “fuel the Russian war machine” was part of his trip to show his support for Kyiv.

According to him, the military aid package will include air surveillance radars, anti-armor systems, and artillery ammunition “to help protect the Ukrainian people from aerial bombardments.”

“Freedom is priceless. It is worth fighting for as long as it takes. And that’s how long we’re going to be with you, Mr. President. As long as it takes,” Biden told President Volodymyr Zelenskiy after talks.

Biden appeared to make no mention of fighter jets, which Ukraine has been seeking from Western allies to help it push back the Russian forces.

Air raid sirens blared as Biden, 80, walked with Zelenskiy through central Kyiv but there were no reports of Russian missile or air strikes.

“The cost that Ukraine has had to pay is extraordinarily high. Sacrifices have been far too great,” Biden told reporters.

Describing the trip as “historic”, Ukrainian Foreign Minister Dmytro Kuleba said both Biden and Zelenskiy were pleased with their talks and that the visit sent a message of resolve to Russia, which he called “the swamp”.

“This visit is the victory of the Ukrainian people and President Zelenskiy… It is a clear signal to the swamp – no one is afraid of you!” he said.

Visiting Kyiv for the first time since Russia’s invasion on Feb. 24, 2022, Biden said Washington would stand with Ukraine as long as it takes.