Donald Trump claimed he had "automatic chemistry" with the Queen and has "really got to know" her during their private meetings, as he ended his five-day trip to Europe.
The US president has long spoken of his respect for the Queen and called her a "great, great woman" during his official State Visit to the UK earlier this week, reports Telegraph UK.
But in an interview with Fox News, he seemed to suggest the 93-year-old monarch was just as taken with him, suggesting the Queen had never had "a better time" as they chatted for hours on end.
"The meeting with the Queen was incredible. I think I can say I've really got to know her because I've sat with her many times and we had automatic chemistry," he told the US cable network.
"You understand that feeling, it's a good feeling. But she's a spectacular woman".
Mr Trump also denied claims he had "fist bumped" the Queen as they greeted each other at Buckingham Palace on Monday, after pictures of the meeting appeared to suggest he had breached protocol.
"I did not - but I had a great relationship. We had a really great time," he said, before adding: "There are those that say they have never seen the Queen have a better time, a more animated time."
"We had a period where we were talking solid, straight, I didn't even know who the other people at the table were, never spoke to them," he claimed.
The president appeared to be at pains to observe royal protocol as he was welcomed to Buckingham Palace on his first day in London by the Queen, the Prince of Wales and the Duchess of Cornwall.
He went on to praise the monarch as a "great, great woman" during a State Banquet hosted by her majesty and other senior members of the Royal family and could be seen smiling at her in Portsmouth on Wednesday at an event to commemorate the Allied forces.
He shared details about the pair's relationship in a pre-recorded interview while he was at the Normandy American cemetery on Thursday as part of a ceremony to commemorate the 75th anniversary of the D-Day landings.
During the lengthy interview he also hit out at Nancy Pelosi, the Democratic leader of the House of Representatives, who reportedly suggested she would like to see the president "in prison" earlier this week.
Mrs Pelosi is facing pressure from members of her own party to begin impeachment proceedings against Mr Trump. But according to the website Politico, earlier this week she told those leading the effort to focus their energy on defeating Mr Trump in 2020 - since he can be prosecuted for his alleged crimes once he has left office.
Hitting back at the reports, the president mocked the House Speaker as "Nervous Nancy" and a "disaster" in response to the reports and said special counsel Robert Mueller, had made "a fool out of himself" with his investigation of the president.
Mr Trump later flew to Ireland, where he ended his European trip by playing a round of golf at his luxury coastal resort in Doonbeg, Co Clare.
Mr Trump and First Lady Melania Trump flew out of Shannon Airport on Air Force One Friday afternoon having spent two nights at his five-star hotel.