US President Donald Trump insists the NHS will be part of a trade deal with Britain, during a joint news conference with Prime Minister Theresa May.
The NHS would be on the table during negotiations on a post-Brexit trade deal with the US, he said, adding: "I think everything with a trade deal is on the table. When you're dealing in trade everything is on the table so NHS or anything else, a lot more than that, but everything will be on the table, absolutely."
Mrs May interjected: "But the point in making trade deals is of course that both sides negotiate and come to an agreement about what should or should not be in that trade deal for the future."
Mr Trump said he believed Brexit should and will happen and promised "phenomenal" trade deal would follow.
"Our nations have more than 1 trillion dollars invested in each other's economics. As the UK makes preparations to exit the EU the US is committed to a phenomenal trade deal between the US and the UK.
"There is tremendous potential in that trade deal, I say probably two and even three times what we're doing right now."
Earlier, Labour leader Jeremy Corbyn vowed to oppose a Brexit deal that includes "our precious NHS to be taken over by American companies".
He told a protest in central London: "We won't stand for that. We will fight for that with every last breath of our body to defend the principle of a healthcare system as free at the point of need as a human right."