WASHINGTON (AP) — Now a done deal, the Iran nuclear agreement gained the backing of two more senators Thursday, boosting supporters' hopes they can block a disapproval resolution in the Senate and spare President Barack Obama from resorting to a veto.

Democratic Sen. Cory Booker of New Jersey bucked home-state pressures and the state's senior senator, Democrat Bob Menendez, to announce he would side with Obama.

"It is better to support a deeply flawed deal, for the alternative is worse. Thus, I will vote in support of the deal," Booker said. "But the United States must recognize that to make this deal work, we must be more vigilant than ever in fighting Iranian aggression."

Not long after, Sen. Mark Warner, D-Va., said in a statement that the accord negotiated by world powers was "the best option for advancing the goal of keeping Iran from obtaining a nuclear weapon."

On Wednesday, Senate Democrats clinched the needed votes to uphold Obama's veto, if necessary, of a resolution of disapproval that Republicans are trying to pass this month. Booker and Warner became the 35th and 36th Democratic or independent senator to back the deal.

Supporters are aiming to collect 41 votes in favor, which would allow them to block a final vote on the disapproval resolution in the Senate and save Obama from exercising his veto power.

For opponents, the challenge now is the opposite: to prevent a filibuster of the agreement and ensure congressional passage of a resolution putting Congress on record against the deal, even with the certainty that the measure will be vetoed.

"Since it looked like the administration was closing in on enough votes to sustain a presidential veto we've been asking people, just in fairness, 'Let this come to a vote,'" said former Democratic-turned-independent Sen. Joe Lieberman, who's rallying opposition to the deal.

House Republican leaders moved up debate on the disapproval resolution to next week, ensuring that the House will go on record against the deal shortly after Congress returns from its August recess, regardless of the outcome in the Senate. GOP lawmakers who control the House and Senate say Iran got too many concessions in the agreement.

Democratic supporters claimed a decisive 34 votes in favor of the deal in the Senate after Sen. Barbara Mikulski of Maryland called the pact "the best option available to block Iran from having a nuclear bomb."

Senate Majority Leader Mitch McConnell, R-Ky., grudgingly acknowledged that his side would not be able to block the deal, which he said leaves Iran "with a threshold nuclear capability."

Israel contends the deal would keep Iran perilously close to developing nuclear weapons while enriching a government that has funded anti-U.S. and anti-Israel militants throughout the Middle East.

White House press secretary Josh Earnest called the growing support a validation of Obama's effort to "make sure that every member of the Senate understands exactly what's included in the agreement."

The deal sets Iran back so that it is at least a year away from being able to produce enough nuclear material for a weapon, before the restrictions ease after a decade.

In Tehran on Thursday, Iran's supreme leader, Ayatollah Ali Khamenei, said "there will be no deal" if world powers merely suspend economic sanctions rather than lifting them. His remarks were read by a state TV anchorman.

Khamenei said some U.S. officials have spoken of the "suspension" of the sanctions, which he said is unacceptable. He said that Iran will only partially comply with its commitments if the sanctions are merely suspended.