US Speaker of the House Nancy Pelosi claimed that British Prime Minister Boris Johnson has the power to approve new drugs before they pass clinical trials.
Pelosi's gaffe came in response to a question from Sky News Scotland bureau chief James Matthews.
Matthews, noting that Pelosi has previously criticized Johnson over his implementation of the UK's vote to leave the European Union, asked if she thought that the PM is unfit to lead the UK government after his bout with the coronavirus six months earlier.
"I have no idea, nor do I have of President Trump," Pelosi admitted, before claiming: "Clearly he is on medication. Any of us who is under medication of that seriousness is in an altered state."
The speaker claimed her real concern was that Trump would "embrace" a British-developed vaccine for COVID-19 and that the UK drug licensing agency was "not on a par" with the US Food and Drug Administration.
"I think we have to be very careful about what happens in the UK," she said. "My concern is that the UK’s system for that kind of judgment is not on a par with ours in the United States."
"So if Boris Johnson decides if he’s going to approve a drug, and this president embraces that, that’s a concern that I have about any similarity between the two."
BBC economics editor Faisal Islam commented: "Blimey."
— Faisal Islam (@faisalislam) October 9, 2020
British prime ministers have no say in licensing drugs and vaccines, which is governed by the Medicines and Healthcare Products Regulatory Agency.
Research into a COVID-19 vaccine has been underway at the UK's Oxford University since April. Unconfirmed media reports on Thursday said large-scale trials involving tens of thousands of subjects could begin in November. However, the vaccine requires a booster 28 days after the first dose, complicating a quick roll-out.
The UK had some 17,500 active coronavirus cases as of Thursday amid a new spike in infections. Nearly 43,000 have died in the pandemic since March.
Johnson was discharged from St Thomas Hospital, a major National Health Service facility across the Thames from Parliament, on April 12 after several days in intensive care after testing positive for COVID-19. He returned to work two weeks later, with Foreign Secretary Dominic Raab deputising for him in the meantime.
Trump and his wife Melania were admitted last Friday October 2 to the Walter Reed Medical Centre near Washington DC for four days after they both tested positive for the virus. Trump returned to the White House on Monday evening.