Putin officially pulls Russia out of the Open Skies arms-control treaty. Trump quit the pact last year.

• Russian President Vladimir Putin withdrew Russia from the Open Skies arms control treaty on Monday.
• Trump pulled the US out of the treaty last year, and Biden said he would not resign.
• Putin said the US decision to pull out "significantly upset the balance of interests" among members of the treaty.

Vladimir Putin formally withdrew Russia from the Open Skies arms control treaty on Monday.

The move comes one year after Former President Donald Trump pulled the US out of the treaty, which allows unarmed surveillance between countries in the agreement.

President Joe Biden said in May that he would not re-enter the pact.

Putin formalized Russia's exit from the treaty with a new law on Monday, saying the US decision to pull out "significantly upset the balance of interests" among members of the treaty, according to Reuters.

"This caused serious damage to the treaty's observance and its significance in building confidence and transparency, (causing) a threat to Russia's national security," the Kremlin said in a statement translated by Reuters.

This is a developing story. Please check back for more updates.