Senator Maria Cantwell
Senator Maria CantwellReuters

Senator Maria Cantwell (D-WA) said Tuesday she supports the Iran deal, thus becoming the last Senate Democrat to take a position on the agreement.

"I am supportive of the deal. Anything that can move it forward I'll support," she told reporters, according to The Hill.

Cantwell is the 42nd senator to back the agreement, after Richard Blumenthal (D-CT), Gary Peters (D-MI) and Ron Wyden (D-OR) came out in support earlier Tuesday, giving President Barack Obama sufficient Senate support to prevent the Republicans from torpedoing his accord.

Cantwell added that she would also support a filibuster of the vote on a resolution to disapprove the deal. 

Cantwell's support comes after near-silence on the agreement since it was announced in mid-July, noted The Hill. She was expected to support the deal, however, being a blue-state Democrat who isn't up for reelection next year.

 In a separate statement, Cantwell said the United States "must remain committed to holding Iran accountable for its behavior in the region... through the U.S. sanctions that will remain in place "

"Nothing in the [nuclear agreement] prohibits or in any way limits the ability of the United States to take these actions," she added. "The global community should do the same."

Four Senate Democrats stand opposed to the agreement, including Chuck Schumer, who is expected to be the next Democratic leader in 2017. Also among those who are opposed are New Jersey's Bob Menendez and Maryland’s Ben Cardin.

The Senate is expected to spend this week debating a resolution of disapproval on the Iran nuclear deal, with Congress facing a September 17 deadline to pass legislation.

Meanwhile, AFP reported, the White House made the president's veto threat official Tuesday, warning that sabotaging the agreement would prod Iran into resuming its nuclear program.

"Enactment of the resolution would deal a devastating blow to America's credibility as a leader of diplomacy and could ultimately result in the exhaustion of alternatives to military action," the White House budget office said in a statement.