There are concerns President Donald Trump could soon remove the U.S. from a key international treaty.
On Monday, New York democratic Representative Eliot Engel warned the U.S. could leave the “Open Skies” Treaty.
In the letter to a national security advisor Engel released publicly, he said such a move “Risks dividing the Transatlantic Alliance.”
The Open Skies Treaty went into effect in 2002.
It allows 34 member states to conduct unarmed surveillance flights over one another’s territories and is used to help verify arms control agreements.
The White House and Pentagon have not responded to requests for comment on the matter.