The U.S. ambassador to the United Nations sought to reassure Congress on June 16 that sanctions could be easily reimposed on Tehran if it does not curb nuclear weapons development under any agreement with world powers.
U.S. President Barack Obama has said he wants sanctions to "snap back" automatically if Iran cheats. This "snap-back mechanism" has been his main defense of the proposed pact from the opposition in Congress.
But Russian and Iranian negotiators have shunned any automatic reimposition of sanctions and are discussing instead having the United Nations Security Council vote on reimposing them.
Members of the House Foreign Affairs Committee told UN Ambassador Samantha Power that they fear Russia and China might use their veto authority as permanent Security Council members to prevent sanctions from snapping back into place under that scheme.
But she assured that the United States will "not allow snap-back to be left in the hands of Russia or China."
Without providing details, she said, "We will retain the ability to snap back multilateral sanctions in place without Russian or Chinese support."