WASHINGTON — President Obama leaned heavily on Congress today to not take any action against Iran as the administration finally began moving on a six-month-long agreement worked out nearly two months ago.

At an Oval Office appearance with Spanish President Mariano Rajoy Brey this afternoon, Obama urged the Senate — which is quickly approaching a veto-proof majority of co-sponsors — to stand down on the bill from Senate Foreign Relations Committee Chairman Robert Menendez (D-N.J.) and Sen. Mark Kirk (R-Ill.) and give the White House and Tehran “the time and space” for their deal to work.

“It’s going to be difficult, it’s going to be challenging, but ultimately this is how diplomacy should work,” Obama said. “…My preference is for peace and diplomacy, and this is one of the reasons why I’ve sent the message to Congress that  now is not the time for us to impose new sanctions, now is the time for us to allow the diplomats and technical experts to do their work.”

“What we want to do is give diplomacy a chance, and give peace a chance.”

The White House announced Sunday the implementation of the “first step agreement” on Iran’s nuclear program.

“Beginning January 20th, Iran will for the first time start eliminating its stockpile of higher levels of enriched uranium and dismantling some of the infrastructure that makes such enrichment possible,” Obama said in a statement. “…In return, over the next six months the United States and our P5+1 partners — the United Kingdom, France, Germany, Russia, and China, as well as the European Union –- will begin to implement modest relief so long as Iran fulfills its obligations and as we pursue a comprehensive solution to Iran’s nuclear program.”

“Unprecedented sanctions and tough diplomacy helped to bring Iran to the negotiating table, and I’m grateful to our partners in Congress who share our goal of preventing Iran from acquiring a nuclear weapon. Imposing additional sanctions now will only risk derailing our efforts to resolve this issue peacefully, and I will veto any legislation enacting new sanctions during the negotiation,” he added.

But some informal whip counts put the number of “yes” votes in the upper chamber as high as 77, overriding a presidential veto. The bill currently has 59 co-sponsors and climbing.

The overwhelming bipartisan support can force Majority Leader Harry Reid’s (D-Nev.) hand in bringing the legislation to the floor; Reid said before Thanksgiving that he supported new sanctions on the Islamic Republic but quieted down after an apparent talking-to from the White House. One aide told CNN that the bill could come to the floor the week of Obama’s State of the Union address.

Secretary of State John Kerry said in a statement that he “very much” appreciates “Congress’ critical role in imposing the sanctions that brought Iran to the table, but I feel just as strongly that now is not the time to impose additional sanctions that could threaten the entire negotiating process.”

“Now is not the time for politics,” Kerry said. “Now is the time for statesmanship, for the good of our country, the region, and the world.”

The bill is even more poignant as it was crafted and introduced by Kerry’s successor on the Foreign Relations Committee, Menendez, who has expressed incredulity at how the administration can put so much trust in the regime.

Menendez wrote in a Washington Post op-ed late last week that the sanctions bill “is an act of reasonable pragmatism” acting like a “diplomatic insurance policy” for the Obama administration’s negotiations.

Since Kerry forged the agreement with Iran in November, Menendez stressed, Iran has continued construction at the Arak heavy water reactor, has built additional centrifuges and admitted it has more than originally disclosed, and fired a rocket into space and showcased long-range ballistic missile capability. The Iranian parliament is also weighing a bill to increase uranium up to 60 percent, and the Iranian walkout from negotiations when the Treasury Department blacklisted 19 companies for evading sanctions last month demonstrated the regime’s “customary bluff-and-bluster techniques.”

Iran stressed that the P5+1 agreement let them proceed with their “new generation” centrifuges for “research purposes.”