President Barack Obama said Saturday that partisan wrangling over the emerging nuclear agreement with Iran and on other foreign policy matters has gone beyond the pale, singling out two senior Republican senators for particularly harsh criticism. “It needs to stop,” he declared.

Obama complained that Sen. John McCain of Arizona had suggested that U.S. Secretary of State John Kerry’s explanations of the framework agreement with Iran were “somehow less trustworthy” than those of Iran’s supreme leader.

“That’s an indication of the degree to which partisanship has crossed all boundaries,” an exercised Obama said in a news conference at the end of the two-day Summit of the Americas. “And we’re seeing this again and again.”

McCain returned the criticism, arguing in a statement that the discrepancies between the U.S. and Iranian versions of the deal extended to inspections, sanctions relief and other key issues.

“It is undeniable that the version of the nuclear agreement outlined by the Obama administration is far different from the one described by Iran’s supreme leader,” McCain said in a statement.

Obama, speaking at a news conference in Panama City, said it was understandable that people would be suspicious of Iran, even that they would oppose the nuclear deal.

“But when you start getting to the point where you are actively communicating that the United States government and our secretary of state is somehow spinning presentations in a negotiation with a foreign power, particularly one you say is your enemy, that’s a problem,” he said.

Clearly irked by aggressive pushback from the strengthened Republican majority in Congress, Obama also singled out Senate Majority Leader Mitch McConnell for criticism, saying the Kentucky Republican had been “telling the world” not to have confidence that the U.S. can meet its own climate change goals.

McConnell has been urging U.S. states not to comply with Obama’s power plant rules, and arguing that the U.S. could never meet Obama’s target even if those rules do survive.

Obama also renewed his complaints about the 47 Republican senators who sent a letter to Iran’s leaders saying that any deal the Iranians made with the U.S. wouldn’t necessarily hold up after Obama leaves office.

Of all of it, Obama said: “That’s not how we’re supposed to run foreign policy regardless of who’s president or secretary of state.”

Obama said he’s still “absolutely positive” that the framework agreement is the best way to prevent Iran from getting a nuclear weapon. And he added that if the final negotiations don’t produce a tough enough agreement, the U.S. can back away from it.

The president added that instead of working to make the nuclear deal better, GOP critics seemed out to sink it.

“I don’t understand why it is that everybody’s working so hard to anticipate failure,” he said.

McCain last week said that comments by Iran’s supreme leader had suggested that Iran and the Obama administration were on different pages. McCain called the supreme leader’s suggestion that Iran wouldn’t allow unlimited inspections “a major setback,” adding that it was the supreme leader, not President Hassan Rouhani or Iran’s foreign minister, who really calls the shots in Iran.

“These differences need to be thoroughly explained by the administration if we are to give serious consideration to this agreement,” McCain said.

McCain, the Senate Armed Services Committee chairman, was among the signatories to the GOP letter to Iran’s leaders warning that any deal struck with Obama would be “a mere executive agreement” that the next president could revoke. In the days since, McCain has stood by the letter’s sentiment while acknowledging that writing to the leadership in Tehran had not been the most effective move. Kerry has denounced that letter as “unconstitutional.”

The Senate Foreign Relations Committee is set to debate and begin voting Tuesday on amendments to legislation calling for Congress to have a say on the nuclear agreement.

Obama opposes the bill as written and has pledged to veto it, but lawmakers on both sides of the aisle have proposed numerous amendments to either make a final deal impossible to reach or to give the White House more leeway to negotiate with Iran.

Under the bill, Obama could unilaterally lift or ease any sanctions that were imposed on Iran through presidential action. But he would be prohibited for 60 days from suspending, waiving or otherwise easing any sanctions Congress levied on Iran.

(AP)