US President Barack Obama has hailed a Congressional vote allowing a nuclear deal with Iran to go ahead, saying work will now shift to implementing and verifying the accord.
"This vote is a victory for diplomacy, for American national security, and for the safety and security of the world," Obama said in a written statement.
Senators fell two votes shy of the 60 needed to advance a resolution disapproving of the international accord, meaning the legislation aimed at sabotaging the deal is essentially dead.
The Iran agreement offers sanctions relief in exchange for curbs on Iran's nuclear program.
It is rare for a US president to fail to secure Congress's backing for a major foreign policy initiative. But Thursday's vote is being seen as a victory for the White House nonetheless.
After a bitter and lengthy campaign to wrangle votes, wining over the support of 42 Senators saved Obama the embarrassment of having to veto a resolution of disapproval.
"I am heartened that so many Senators judged this deal on the merits, and am gratified by the strong support of lawmakers and citizens alike."
"We will turn to the critical work of implementing and verifying this deal so that Iran cannot pursue a nuclear weapon."