The U.N. Security Council scheduled a vote for first thing Monday morning on a resolution endorsing the Iran nuclear deal.
The resolution was circulated to council members Wednesday by the United States. Members were also briefed by both Iran and the other countries that negotiated the landmark agreement to curb Iran's nuclear program.
With all five veto-wielding permanent members of the Security Council involved in the marathon Iran negotiations, the resolution's adoption Monday was almost certain.
The resolution implements an intricate deal that places restrictions on Iran's nuclear program while allowing relief from sanctions that the country's leaders say have hurt its economy.
Monday's vote came despite calls from some U.S. lawmakers to delay Security Council approval until Congress reviews the deal.
The chairman of the Senate's foreign relations committee, Bob Corker, on Thursday wrote a letter to President Barack Obama saying, "We urge you to postpone the vote at the United Nations until after Congress considers this agreement."
But the chief U.S. negotiator in the Iran talks, Wendy Sherman, rejected that idea Thursday.
She told reporters: "It would have been a little difficult when all of the (countries negotiating with Iran) wanted to go to the United Nations to get an endorsement of this, since it is a product of the United Nations process, for us to say, 'Well, excuse me, the world, you should wait for the United States Congress.'"
Sherman said the council resolution allows the "time and space" for a congressional review before the measure actually takes effect.