U.S. Secretary of State Antony Blinken on Friday said that the United States approved the use of U.S. weapons by Ukraine across the border inside Russia after Kyiv asked for authorization over the past few weeks amid Russia's attacks on Kharkiv.

Blinken, speaking to reporters in the Czech Republic following a meeting of NATO foreign ministers, said U.S. President Joe Biden had approved the move. 

But he did not specifically say whether Biden's authorization could expand to include other Russian cities and targets that are deeper inside Russia.