Hiroshima, Japan (CNN) — President Joe Biden issued a stark warning Sunday that congressional Republicans could use a national default to damage him politically and acknowledged time had run out to use potential unilateral actions to raise the federal borrowing limit, a sharp shift in tone days before the deadline to reach an agreement.

Characterizing GOP proposals as “extreme” and warning they couldn’t gain sufficient support in Congress, Biden said he wasn’t able to promise fellow world leaders gathered in Japan for Group of 7 talks the US would not default.

“I can’t guarantee that they will not force a default by doing something outrageous,” he said.

Biden’s remarks, delivered as he prepared to return to Washington, were the latest indication that talks between the White House and congressional Republicans remain far apart.

He was expected to speak by phone with House Speaker Kevin McCarthy shortly after taking off aboard Air Force One, though it wasn’t clear whether that conversation would break the logjam.

“My guess is he’s going to want to deal directly with me in making sure we’re all on the same page,” he said.

Republicans have been seeking spending cuts in the federal budget in exchange for their support to raise the nation’s borrowing limit. On Sunday, Biden acknowledged “significant” disagreement with Republicans in some areas, insisting that while he’s willing to cut spending, tax “revenue is not off the table” as part of the deal.

“Much of what they’ve already proposed is simply, quite frankly, unacceptable,” Biden said at the news conference. “It’s time for Republicans to accept that there’s no bipartisan deal to be made solely, solely on their partisan terms. … They have to move, as well.”

Pressed on whether he would be to blame for a default scenario, he said that based on what he’s offered, he should be blameless, but conceded that “no one will be blameless” as he suggested some of his political rivals could be encouraging a default to sabotage his reelection efforts.

“I think there are some MAGA Republicans in the House who know the damage it would do to the economy, and because I am president, and a president is responsible for everything, Biden would take the blame and that’s the one way to make sure Biden’s not reelected,” he said.


Biden outlines shortcomings of 14th Amendment argument


Biden also addressed the possibility of using the 14th Amendment to continue US government borrowing in the absence of a deal, suggesting he has the power but not the time to utilize the unilateral action.

“I think we have the authority. The question is, could it be done and invoked in time that it could not – would not be appealed?” Biden asked, calling the question of whether an appeal could be solved before the default deadline “unresolved.”

Pressed by CNN’s Phil Mattingly to clarify whether he thought he could invoke the 14th Amendment as a serious and tangible option, the president made clear that maneuver would not be successful given the short window remaining.

“We have not come up with unilateral action that could succeed in a matter of two weeks or three weeks. That’s the issue. So it’s up to lawmakers. But my hope and intention is to resolve this problem,” he said.

Treasury Secretary Janet Yellen has warned the US could default on its debts as soon as June 1.


Talks at a standoff in Washington


On Saturday afternoon, McCarthy said negotiators wouldn’t be able to resume talks with the administration until Biden was back in Washington.

“Unfortunately, the White House moved backwards,” the California Republican said. “I don’t think we’re going to be able to move forward until the President can get back.”

Biden has been traveling overseas to attend the Group of 7 summit in Hiroshima, Japan, since leaving Washington on Wednesday. Biden is slated to fly back to DC on Sunday, a shortened version of his trip that originally had stops in Australia and Papua New Guinea before Biden cut the final legs amid debt ceiling talks.

Biden asked his team to coordinate with the speaker to arrange the conversation on Sunday morning Eastern Time, which would be the two men’s first conversation since debt talks appeared to stall amid disputes over spending limits.

Republican Rep. Dusty Johnson of South Dakota confirmed on Saturday that the White House made an offer seeking to cap future spending at current levels, which Johnson called “unreasonable.”

Johnson, a McCarthy ally and chair of the centrist Main Street Caucus, is one of several key players who has been getting briefed by Republican negotiators on the talks.

“Negotiations did not go well today,” Johnson said. “The paper that the White House provided was a major step backward. And it undermined all the progress that was made Wednesday and Thursday. … It has endangered negotiations.”

Johnson warned, “We are at real risk of default.”

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