Trump begins UK visit meeting Queen, sparring with London mayor

President Trump mixed high-level diplomacy with schoolyard taunts as he kicked off his overseas visit meeting with Queen Elizabeth II at Buckingham Palace and later touring Westminster Abbey -- while sparring on the side with one of his biggest British critics, London Mayor Sadiq Khan.

The London itinerary is part of a packed overseas agenda that includes a state dinner at the palace and D-Day commemoration ceremonies.

At their initial visit to the palace early Monday morning, the president and first lady Melania Trump had a private lunch with the Queen, later inspecting a collection of artifacts including an 18th-century map of New York, historic photos of golf at St. Andrews and books about birds and George Washington. He then participated in a wreath-laying at the Grave of the Unknown Warrior at Westminster Abbey.

The visit began with formalities befitting a state visit. The Trumps were greeted by Prince Charles and his wife Camilla, the Duchess of Cornwall, at the palace. Trump could be seen chatting with members of the Guard of Honor as the rest of the American delegation, from a terrace, observed the elaborate arrival ceremony, complete with the playing of “The Star-Spangled Banner.” Royal gun salutes were fired from nearby Green Park and from the Tower of London as part of the pageantry accompanying an official state visit.

Juxtaposed against that scene, however, was an opening scrap between Trump and London Mayor Khan, who penned a critical column of the president he called a "global threat." In the column titled, “It’s un-British to roll out the red carpet for Donald Trump,” Khan listed Trump’s most controversial policies and likened them to the actions of European dictators of the 1930s and 40s.