Republican Kevin McCarthy has picked up the support of most of the right-wing hardliners who had opposed his bid to lead the United States House of Representatives but has fallen short of clinching victory in the 13th ballot in four days.

The California lawmaker said he believed victory was close, and the chamber voted to reconvene at 10pm ET (0300 GMT Saturday).

McCarthy claimed the four-day stand-off within his party would come to an end then.

McCarthy supporters and some Democrats worried the concessions he made in hopes of securing the House speakership, including agreeing to allow any single member to call for a vote to remove him from office at any time, could extend the deepest congressional dysfunction in more than 150 years.

Three votes short

McCarthy gained backing on Friday from 15 of his former hardline opponents but drew just 214 votes in total, three short of the 217 needed if all 434 current members of the House vote.

The path to a winning tally depends on the ever-shifting maths of where his six remaining hardline opponents stand and whether two McCarthy supporters who had left Washington return on Friday.

“It’s going to happen,” McCarthy said, predicting a Friday night victory.

Republicans’ weaker-than-expected performance in November’s midterm elections left them with a narrow 222-212 majority, which has given outsized power to the right-wing hardliners who have opposed McCarthy’s leadership.

They accuse him of being too open to compromise with President Joe Biden and his Democrats, who also control the US Senate.

Some say they want a leader who will be ready to force government shutdowns to cut spending.

That raises the possibility the two parties would fail to reach a deal when the federal government comes up against its $US31.4 ($A45.8) trillion debt limit this year.

A lack of agreement or even a long stand-off risks a default that would shake the global economy.

Representative Scott Perry, the chairman of the hard-right House Freedom Caucus, said he changed his vote to support McCarthy because McCarthy agreed to profound changes in how the House approves spending.

“You have changes in how we’re going to spend and allocate money that are going to be historic,” Perry said.

“We don’t want clean debt ceilings to just go through and just keep paying the bill without some counteracting effort to control spending when the Democrats control the White House and control the Senate.”

Congress needs to raise the debt ceiling to pay for spending it has already authorised. Debt ceiling increases do not authorise new spending on their own.

Politics of  ‘obstruction’

The remaining holdouts faced increasing pressure to fall into line and allow Republicans to take control of the chamber after some warned the long stand-off raised questions about the party’s ability to govern.

“It has become clear to me that a couple of individuals are simply obstructionists,” said Keith Self, a newly elected Texas Republican, after switching his vote.

It was unclear what – if anything – McCarthy could do to win them over.

Of the 20 Republicans who this week have cast votes opposing McCarthy, 14 received campaign contributions totaling just $US120,000 ($A174,962) ahead of the midterms from the McCarthy-controlled Majority Committee fundraising group, federal disclosures show.

The House remained leaderless and unable to begin its business on Friday, the two-year anniversary of a January 6, 2021, attack on the US Capitol when a violent mob stormed Congress in an attempt to overturn then-President Trump’s election loss.

This week’s 13 failed votes marked the highest number of ballots for the speakership since 1859 on the eve of the Civil War.

-AAP