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.