LONDON — President Donald Trump touched down in the U.K. on Monday night ahead of a highly anticipated NATO meeting, marking 70 years since the alliance's creation.

The gathering comes amid overt tensions between some leaders regarding spending pledges, how to tackle the challenges posed by Russia and China, and the relevance of NATO itself.

The two-day meeting is taking place just outside of London, in Watford, with high-profile delegates then heading to Buckingham Palace in the evening where Queen Elizabeth II will host NATO heads of state and government for dinner.

Having met with NATO Secretary General Jens Stoltenberg on Tuesday morning, Trump gave a press conference with the NATO chief in which he commented on a range of subjects, from Turkey's involvement in Syria to a potential post-Brexit trade deal with the U.K.

Trump insisted that access to the U.K.'s National Health Service in a potential deal — a possibility that has caused a stir in the U.K. — would not interest the U.S., "even if it was presented on a silver platter." He also discussed developments in a potential U.S.-China trade deal.

Trump is scheduled to have talks with French President Emmanuel Macron on Tuesday and German Chancellor Angela Merkel on Wednesday. It's unclear if the U.S. president will meet with Prime Minister Boris Johnson with the U.K. leader apparently keen for Trump not to involve himself in Britain's domestic politics ahead of an upcoming election on Dec. 12.