NATO Secretary General Jens Stoltenberg, left, and British Prime Minister Boris Johnson, center, greet U.S. President Donald Trump during official arrivals at a NATO leaders meeting at The Grove hotel and resort in Watford, Hertfordshire, England, Wednesday, Dec. 4, 2019. He further said that he can work with anybody in 10-9 days ahead of the United Kingdom elections as he is a very easy person to work with.
The president added: "I don't even know where that rumour started".
He has held up a new U.S. trade deal as one of the prizes of Brexit but has faced accusations from Labour that this will open up the much loved NHS to United States firms.
But he has previously questioned whether the terms Johnson has struck with Brussels would allow Britain to make a trade deal with the US.
Johnson's pressure prompted the White House to stress, as a senior administration official said, that Trump "is absolutely cognizant of not, again, wading into other country's elections".
In his previous speeches, Trump had acknowledged Johnson as Britain's Trump and also described him as the most capable leader to conclude Brexit.
Leaders including Mr Trump and Mr Corbyn will gather for a reception at Buckingham Palace tonight.
The next day, the US president called Canada's prime minister "two-faced" after Justin Trudeau was caught on an open microphone gossiping about Trump at a royal reception.
Meanwhile, the president - who said yesterday that America wants "nothing to do with" the NHS despite Labour's claims it would be up for sale - tweeted that he had "enjoyed" his off-camera meeting with the PM on Tuesday evening, and said they talked about "numerous subjects". There were no immediate details of a one-to-one meeting.
In a speech, Mr Johnson will tell the other North Atlantic Treaty Organisation leaders: "Seventy years on, we are rock solid in our commitment to North Atlantic Treaty Organisation and to the giant shield of solidarity that now protects 29 countries and almost a billion people".
Asked where they came from after it was suggested they may have made it to Reddit via Russian hackers, the Labour leader said: "This is such nonsense, such utter nonsense".
"These documents represent secret talks between the Tory Government and the American administration to sell off our public services to American corporations".
"If the document is not accurate then why is it it's been out there all this time, no minister has claimed it's inaccurate, no government has, and in reality the minutes are there of meetings".
"I do think it's a security risk, it's a security danger".
Labour says leaked documents from preliminary trade talks held between 2017 and this year show that drug pricing was part of the agenda.