Boris Johnson has promised to tell Donald Trump that the NHS is “off the table” in negotiations over a post-Brexit trade deal with the US.

The prime minister claimed his red lines for negotiations included any idea of American firms buying parts of the state-funded health service.

He also said the US would have to open its markets to British goods, including lamb and beef, which are barred, and lower its tariffs.

Mr Johnson claimed he would tell the president “that when we do a free trade deal, we must make sure that the NHS is not on the table, that we do not in any way prejudice or jeopardize our standards on animal welfare and food hygiene in the course of that deal, and that we open up American markets.”

He is expected to attempt to lay the groundwork for a trade agreement while meeting Mr Trump this week at the United Nations General Assembly in New York.

Biggest lies told by Boris Johnson Show all 5 1 /5 Biggest lies told by Boris Johnson Biggest lies told by Boris Johnson Made-up quote for The Times Johnson was sacked from The Times newspaper in the late 1980s after he fabricated a quote from his godfather, the historian Colin Lucas, for a front-page article about the discovery of Edward II’s Rose Palace. “The trouble was that somewhere in my copy I managed to attribute to Colin the view that Edward II and Piers Gaveston would have been cavorting together in the Rose Palace,” he claimed. Alas, Gaveston was executed 13 years before the palace was built. “It was very nasty,” Mr Johnson added, before attempting to downplay it as nothing more than a schoolboy blunder. PA Biggest lies told by Boris Johnson Sacked from cabinet over cheating lie Michael Howard gave Boris Johnson two new jobs after becoming leader of the Conservatives in 2003 – party vice-chairman and shadow arts minister. He was sacked from both positions in November 2004 after assuring Mr Howard that tabloid reports of his affair with Spectator columnist Petronella Wyatt were false and an “inverted pyramid of piffle”. When the story was found to be true, he refused to resign. PA Biggest lies told by Boris Johnson Broken promise to boss In 1999 Johnson was offered editorship of The Spectator by owner Conrad Black on the condition that he would not stand as an MP while in the post. In 2001 he stood - and was elected - MP for Henley, though Black did allow him to continue as editor despite calling "ineffably duplicitous" PA Biggest lies told by Boris Johnson Misrepresenting the people of Liverpool As editor of The Spectator, he was forced to apologise for an article in the magazine which blamed drunken Liverpool fans for the 1989 Hillsborough disaster and suggested that the people of the city were wallowing in their victim status. “Anyone, journalist or politician, should say sorry to the people of Liverpool – as I do – for misrepresenting what happened at Hillsborough,” he said. PA Biggest lies told by Boris Johnson ‘I didn’t say anything about Turkey’ Johnson claimed in January, that he did not mention Turkey during the EU referendum campaign. In fact, he co-signed a letter stating that “the only way to avoid having common borders with Turkey is to vote Leave and take back control”. The Vote Leave campaign also produced a poster reading: “Turkey (population 76 million) is joining the EU”

Opponents of Brexit fear the NHS will be opened to private US firms as part of trade negotiations and have suggested the UK would have to accept chlorine-washed chicken, which is banned in the European Union.

They have also raised concerns that Britain aims to become a low-tax, low-regulation economy.

When Mr Trump visited London on a state visit this year he told a press conference he believed the NHS would be up for grabs.

Mr Johnson is due to tell US and Canadian business leaders the UK would “roll out the red carpet” for investors after Brexit, his office said.

He will add that “we want a market that is open to the world, with the most competitive tax rates and the best skilled workforce in the hemisphere”.

However, Mr Johnson is also likely to be dogged by the failure to reach agreement on withdrawal from the EU as the 31 October deadline approaches.

The prime minister told reporters he did not think there would be a “New York breakthrough” in meetings with European leaders at the UN, but added: ”I think a large number of the important partners really do want a deal.”

Meanwhile the EU has indicated that Britain has still not come up with proposals for maintaining an open border between Ireland and Northern Ireland.

Chief EU Brexit negotiator Michel Barnier said Monday that “based on current UK thinking, it is difficult to see how we can arrive at a legally operative solution”.

And after meeting the prime minister, European Council president Donald Tusk tweeted succinctly: “No breakthrough. No breakdown. No time to lose.”

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The prime minister argues that the border can be kept free of customs posts and other obstacles using a technological solution and an all-Ireland zone for animals and agricultural products.

“I think colleagues around the table in Brussels can see how we might do that,” Mr Johnson said. “All it will take is a political will to get there.”