"This package will include further lethal defensive assistance to help Ukraine address the armored, airborne, and other threats it is now facing," Blinken said in a statement.

Blinken said that last fall as Russia started amassing troops on the border with its pro-Western neighbor, President Joe Biden authorized $60 million in immediate military assistance to Ukraine, then another $200 million in December as President Vladimir Putin's threat became more acute.

Now the US is authorizing a third package "as Ukraine fights with courage and pride against Russia's brutal and unprovoked assault," Blinken said.

This means total US security assistance committed to Ukraine over the past year now exceeds a billion dollars, the secretary said.

Blinken did not detail what kind of weaponry was involved.

"It is another clear signal that the United States stands with the people of Ukraine as they defend their sovereign, courageous, and proud nation," he said.

The new assistance follows a series of US and other western sanctions against Russian banks and oligarchs in an effort to punish Putin and his inner circle for the invasion of Ukraine and cripple the Russian economy.