KEY POINTS
  • U.S. Defense Secretary James Mattis said it is not in the country's national security interest for President Donald Trump to abandon the Iran nuclear deal.
  • Trump has lately suggested that he may refuse to certify to Congress that Iran is complying with the landmark 2015 accord.
  • Congress would get the opportunity to vote on reimposing sanctions on Iran if Trump refuses to certify Iran this month.
Secretary of Defense James Mattis testifies before a Senate Armed Services Committee hearing on the "Political and Security Situation in Afghanistan" on Capitol Hill in Washington, October 3, 2017.

U.S. Defense Secretary James Mattis on Tuesday said it would not be in the country's national security interest for President Donald Trump to abandon the Iran nuclear deal.

The secretary's assessment marks one of the strongest public defenses of the deal by an administration official in recent weeks. Trump has lately begun hinting that he may soon take steps to leave the landmark 2015 accord, which put limits on Iran's nuclear program in exchange for sanctions relief.