Treasury Secretary Janet Yellen warned on Thursday that pursuing a political policy of standing on the edge of the abyss over the US debt ceiling crisis might lead to "serious economic costs" even without a default.

Her comments came during a three-day financial summit for G7 members held in Japan, attended by finance ministers and heads of central banks.

US President Joe Biden said on Tuesday that he might not attend the G7 summit for presidents next week if the debt ceiling issue is not resolved by then.

Former US President Donald Trump called on Republicans to default on US debt by refraining from raising the debt ceiling if Democrats did not agree on the spending cuts.

"In my assessment -- and that of economists across the board -- a default on US obligations would produce an economic and financial catastrophe," Yellen said in a speech.

"Short of a default, brinkmanship over the debt limit can also impose serious economic costs," she added.

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Last week Yellen warned that the Treasury Department is exhausting its available measures to avoid a default.

"We've been using extraordinary measures for several months now and our ability to do that is running out," she said then.

On Thursday, she said there is "no good reason to generate a crisis of our own making" after recalling a similar situation in 2011 which led to the US losing its AAA debt rating.

"The US Congress has raised or suspended the debt limit almost 80 times since 1960. I urge it to act quickly to do so once again."

Biden met in the White House on Tuesday with bipartisan congressional leaders to discuss the matter. But the talks did not yield an outcome.

Another round of talks between the parties will be held on Friday.