WASHINGTON (AFP) - The top Republican in the US House of Representatives faced calls to apologise or resign on Sunday (Aug 1) after joking about hitting speaker Nancy Pelosi in the head with a gavel.

It was the latest round in a nasty spat between the Republican minority leader Mr Kevin McCarthy and Ms Pelosi, the chamber's top Democrat.

Last week Ms Pelosi called her Republican counterpart a "moron" for opposing mask mandates to fight the Covid-19 pandemic as the Delta variant causes a surge in cases in America.

At a fundraising dinner Saturday night in Tennessee, Mr McCarthy spoke with optimism about prospects for his party retaking the House in mid-term elections next year.

And he went on to joke that - should he become speaker - he would struggle to resist striking Ms Pelosi with the gavel that comes with the job.

"It will be hard not to hit her with it but I will bang it down," Mr McCarthy said, according to a Washington Post reporter who was at the event.

Democrats pounced on Mr McCarthy on Sunday.

"Don't you think America has had enough political violence," tweeted Representative Ted Lieu of California. "You need to apologise for your statement, or resign."

Fellow California Representative Eric Swalwell said Mr McCarthy "needs to resign", tweeting: "America has suffered enough violence around politics."

Representative Debbie Dingell of Michigan insisted Mr McCarthy apologise right away.

"Language like this led to violence and death at the United States Capitol. @GOPLeader knows his words carry weight," Ms Dingell said.

She appeared to be referring to then president Donald Trump's fiery language in a Jan 6 speech to a crowd that went on to overrun the US Capitol as Congress was certifying Mr Joe Biden's election win.

Ms Pelosi was a main target of the mob as it rampaged through the Capitol, in an insurrection that left five people dead.