Biden pledged an additional USD 800 million in security assistance to Ukraine to help it fight Russia, news agencies reported.
The new package includes drones and anti-armour systems.
Speaking to reporters, Biden said of Putin: "He is a war criminal."
At the request of Ukrainian President Volodymyr Zelensky, Washington will help Ukraine acquire additional long-range missile anti-aircraft systems, the Reuters news agency reported.
NATO defence ministers meeting in Brussels on Wednesday also promised more arms supplies to help Ukraine.
In a speech to the US Congress by video link, Zelensky appealed for tougher sanctions on Russia and more weapons to help his country, including a no-fly zone over Ukraine.
Meanwhile, the US embassy in Kyiv said Russian forces had shot dead 10 people waiting in line for bread in Chernihiv, northeast of Kyiv, Reuters reported.
In the besieged southern port of Mariupol, officials said Russian forces bombed a theatre where civilians, including children, were sheltering.
The governor of the Zaporizhzhia region said Russian forces had fired artillery at a convoy of evacuees from Mariupol, wounding five people. Ukraine's military said children were among the casualties, Reuters reported.
Three people were killed and five wounded after shelling caused a fire at a market in eastern Kharkiv, Ukraine's second city, emergency services said, according to Reuters.
Deputy Prime Minister Iryna Vereshchuk said 400 staff and patients were being held hostage at a hospital Russian forces had captured in Mariupol on Tuesday, Reuters also reported.
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Source: Reuters, IAR, PAP