?Weakness and surrender?: Ted Cruz seeks to move on from Tucker Carlson mauling

Ted Cruz used Twitter on Friday to accuse Joe Biden of signaling "weakness and surrender to Putin" over Ukraine - but the Texas senator could not escape a crisis of his own, stoked by widespread accusations of weakness and surrender in the face of the Fox News host Tucker Carlson, over remarks about the deadly Capitol attack.

On Wednesday, a day before the first anniversary of the attack by supporters of Donald Trump attempting to overturn the election, Cruz described "a violent terrorist attack on the Capitol, where we saw the men and women of law enforcement demonstrate incredible courage".

A police officer who confronted the rioters was one of five people who died.

Nonetheless, having stoked opprobrium in circles where the riot is played down or denied, Cruz went on Carlson's primetime show.

Carlson, widely condemned for promoting conspiracy theories about 6 January, is rumoured to have presidential ambitions in competition with Cruz. He went fiercely on the offensive.

"You called this a 'terror attack' when by no definition was it a terror attack," Carlson said. "That's a lie. You told that lie on purpose, and I'm wondering why you did."

Cruz said: "The way I phrased things yesterday, it was sloppy and it was, frankly, dumb."