"It's very unusual for a head of state to acknowledge lobbying the U.S. Congress," said Mark Dubowitz of the Foundation for Defense of Democracies, a Washington think tank that advises Congress on Iran sanctions. "It shows how the U.K. has been to the left of the U.S. on Iran policy."
Preisdent Obama and U.K. Prime Minister David Cameron pledged to aid Europe in wake of recent terror attacks. Truman National Security Project fellow Bob Stasio joins Sara Murray with analysis.
Mr. Obama said the chances of reaching a deal are still less than 50-50, but the next several months of negotiations will determine "whether or not Iran can get to 'yes.'"
If a deal isn't reached, he said he would ask Congress to pass additional sanctions.
U.S. senators have been holding extensive negotiations over the terms of the new Iran sanctions since returning to Washington this month. Republicans now enjoy a majority in the Senate with 54 seats.