Russia has secretly deployed a missile that American officials argue violates a key arms treaty, presenting a new foreign policy test for President Donald Trump, The New York Times reported Tuesday, citing administration officials.
The development would pose another diplomatic challenge for the president in the early days of his administration. Trump has pledged to improve relations with Russian President Vladimir Putin.
The report comes only hours after a key foreign policy official, National Security Advisor Michael Flynn, resigned following revelations that he misled Vice President Mike Pence about his contact with Russian officials. Some lawmakers have called for a deeper investigation into Flynn's ties with Moscow.
The Obama administration said in 2014 that the cruise missile in question had been tested and violated a 1987 treaty that helped to end the Cold War, according to the Times.
The White House did not immediately respond to CNBC's request for comment.
WATCH: Former Defense secretary warns U.S.-Russian relations could descend into nuclear war