Democrat Bob Casey of Pennsylvania has become the 32nd senator to support the nuclear deal with Iran.
Casey's announcement pushes President Barack Obama to within two votes of the 34 needed to sustain a veto of legislation aimed at blocking the deal.
"I have been among the strongest supporters of the tough sanctions against Iran, which brought the regime to the negotiating table. I will continue to advance legislative efforts that prevent Iran from acquiring a nuclear weapon, exporting terrorism in the region, and committing human rights atrocities at home," Casey said in a statement Tuesday, adding:
"I will vote to support the implementation of the Joint Comprehensive Plan of Action because I believe it is the best option available to prevent Iran from acquiring a nuclear weapon. It places strict limitations on Iran’s nuclear program, requires robust monitoring and verification measures, and grants relief only from nuclear sanctions in exchange for verified actions on Iran’s part."
Earlier Tuesday Sen. Ben Cardin of Maryland, top Democrat on the Foreign Relations Committee, predicted Obama would get to 34 votes by week's end.
