Secretary of State John Kerry says Congress risks scuttling nuclear negotiations with Iran if it moves ahead with new sanctions at this time.
Kerry says the U.S. and other world powers are united in support of an interim deal with Iran. It would offer some sanctions to Tehran relief in exchange for nuclear concessions.
But he says the U.S. could quickly lose its partners if it starts adding sanctions while waiting for an Iranian response. Negotiations are to resume next week.
Kerry spoke prior to testifying before the Senate Banking Committee.
The committee is examining a new package of Iran sanctions, but Democratic and Republican lawmakers are divided on whether to give the administration more time for diplomacy.