This would be the latest major international treaty the administration has abandoned. In August the US formally withdrew from the Intermediate-Range Nuclear Forces Treaty with Russia, ending a landmark arms control pact that has limited the development of ground-based missiles with a range of 500 to 5,500 kilometers.
Analysts fear the developments are likely to prompt a new and dangerous arms race with Moscow and CNN has reported the US military is set to test a new non-nuclear mobile-launched cruise missile developed specifically to challenge Russia in Europe.
In a statement, a State Department spokesperson said they were aware of Democratic lawmakers' letters regarding the treaty.
"We do not comment on Congressional correspondence. We continue to implement the treaty and are in full compliance with our obligations under this Treaty, unlike Russia," the spokesperson said.
The White House and Pentagon have not responded to CNN's requests for comment on the matter.
Democrats have been quick to criticize the impending announcement.
"Pulling out of the Open Skies Treaty, an important multilateral arms control agreement, would be yet another gift from the Trump Administration to (Russian President Vladimir) Putin," the top Democrats on the House Foreign Affairs, House Armed Services, Senate Armed Services and Senate Foreign Relations committees wrote in a letter to Secretary of Defense Mark Esper and Secretary of State Mike Pompeo.
"Not only is there no case for withdrawal on the grounds of national security, there has been no consultation with the Congress or with our allies about this consequential decision. Any action by this administration to withdraw from critical international treaties without the approval of the Senate is deeply concerning," wrote Sen. Bob Menendez of New Jersey, Sen. Jack Reed of Rhode Island, Rep. Eliot Engel of New York and Rep. Adam Smith of Washington state.
The US has in the past accused Moscow of imposing restrictions on flights near its exclave of Kaliningrad, an area between Poland and Lithuania where the Russian military maintains a robust presence.
CNN's Paul LeBlanc, Jennifer Hansler, Jon Ostrower, Peter Morris and Noah Gray contributed to this report.