U.S., Iran trade barbs over landmark 2015 nuclear deal

BEIRUT/WASHINGTON (Reuters) - Iran and the United States traded barbs over the landmark 2015 nuclear deal on Thursday, with the U.S. leader accusing Tehran of not living up to the spirit of the accord and Iran's top diplomat urging Washington to fulfill its own commitments.The exchange came a day after U.S. Secretary of State Rex Tillerson sent a letter to Congress saying Iran was in compliance with the nuclear deal but raising questions about Tehran's role in sponsoring terrorism in the region.