US President Donald Trump and first lady Melania Trump touched down in the United Kingdom on Monday ahead of the NATO summit in London this week.

The couple held hands as they disembarked Air Force One at London Stansted Airport on Monday evening for the three-day visit to the country. Melania Trump sported a bright red coat and black heels for the occasion while POTUS opted for a suit and blue tie. US Ambassador to the UK Woody Johnson welcomed the US first couple to the UK and said it was "great to have them back."

Welcome POTUS and FLOTUS to the UK - it’s great to have them back!

— Ambassador Johnson (@USAmbUK) December 2, 2019

The Trumps left the White House earlier on Monday. In an interesting turn of events, the president nearly forgot his wife Melania as she ran behind him to reach him before they boarded helicopter Marine One at the White House for Andrews Air Force Base in Maryland ahead of their flight to London, reports Mail Online.

Apart from participating in the 70th NATO Summit in Watford on Wednesday, Trump will be attending a formal meeting with UK Prime Minister Boris Johnson. This is Trump's third official trip to Britain during his tenure at the White House.

President Trump is also scheduled to have separate talks with German chancellor Angela Merkel, French president Emmanuel Macron and NATO secretary-general Jens Stoltenberg. He will later attend a working lunch with representatives from Estonia, Greece, Latvia, Poland, Romania, Lithuania, Bulgaria, and the UK.

Donald and Melania Trump arrive in London
US President Donald Trump and First Lady Melania Trump (L) prepare to disembark from Air Force One after landing at Stansted Airport, northeast of London ahead of the upcoming NATO summit. Adrian DENNIS/AFP

The 73-year-old will be attending a reception hosted for world leaders by Queen Elizabeth II at Buckingham Palace on Tuesday, in presence of the members of the royal family. Prince Andrew will not be present at Trump's reception reportedly after the queen banned him from the visit amid allegations of sexual impropriety against him.

It is speculated that the US president will try to wade into Britain election campaign during his visit, even though he earlier clarified he was "absolutely cognisant" of the importance of not interfering in other countries' elections. He was previously also criticised for his opinions of British political leaders and faced demonstrations and protests during his earlier two visits to the country. Also, in a recent video interview, Johnson warned Trump against getting involved in the general election on Thursday, December 12.