US Senate Republican Leader Mitch McConnell has sparked alarm in Washington after suddenly stopping speaking during a media briefing, and appearing to freeze.

Mr McConnell was escorted away from the media after Wednesday’s incident, in which he stared straight ahead, silent and unmoving, for about 20 seconds.

His staff later blamed a bout of lightheadedness in front of the TV cameras, and suggested he needed a rest. But the incident has sparked questions about the 81-year-old Republican leader’s health – and his future.

“Hey Mitch, anything else you want to say? Or should we just go back to your office? Do you want to say anything else to the press?” fellow Republican senator John Barrasso was heard whispering to Mr McConnell, as he grasped his arm.

“Are you good, Mitch?” asked another colleague, Iowa senator Joni Ernst.

Eventually Dr Barrasso ushered Mr McConnell away from the podium and back into his office. Dr Barrasso later revealed that he walked “down the hall” with Mr McConnell, who said nothing to indicate any distress.

One of Mr McConnell’s aides said later that the Republican leader “felt lightheaded and stepped away for a moment”.

“He came back to handle Q and A, which as everyone observed was sharp,” the aide said.

Mr McConnell returned to face journalists only a few minutes later. Asked what happened, he said only “I’m fine”.

He also batted away a question about who might succeed him as Republican leader.

Mr McConnell, 81, has faced questions over his health after suffering a concussion and broken ribs from a fall at a dinner in Washington in March. He was hospitalised and spent weeks in rehab before returning to the Capitol in April.

Dr Barrasso, the No.3 US Republican, said later he was one of those who remained concerned about Mr McConnell.

“I’ve been concerned since he was injured a number of months ago,” he said. “I continue to be concerned.”

The Kentucky senator also spoke to journalists briefly later on Wednesday (local time) as he left the Capitol.

“The President called to check on me,” he said.

“I told him I got sandbagged.”

A White House official and a spokesperson for Mr McConnell confirmed that he had spoken to President Joe Biden on the phone.

House Speaker Kevin McCarthy later told NBC News he met Mr McConnell on Wednesday for a regular catch-up.

“He was good,” Mr McCarthy said. “There was no concerns about his health in the meeting.”

Mr McConnell has been in the US Senate since 1985. He isn’t up for re-election until 2026.

-with agencies