Trump says until Russia adheres to Open Skies treaty 'we will pull out'

The administration said Russia has repeatedly violated the pact's terms. Senior officials said the pullout will formally take place in six months, based on the treaty's withdrawal terms.

"I think we have a very good relationship with Russia. But Russia didn't adhere to the treaty. So until they adhere we will pull out," U.S. President Donald Trump told reporters.

He said there was a "very good chance we'll make a new agreement or do something to put that agreement back together."

NATO allies and other countries such as Ukraine have pressed Washington to remain in the treaty, and Trump's decision could aggravate tensions within the alliance.

The administration also pulled the United States out of the Intermediate-range Nuclear Forces Treaty with Russia last year.

The officials, speaking on condition of anonymity to a small group of reporters, said the decision followed a six-month review that found multiple instances of Russian refusal to comply with the treaty.