When is a visit a state visit?
By CNN's Abid Ali
Bush visited Buckingham Palace in July 2001.
LONDON, England (CNN) -- President George W. Bush becomes the first U.S. president to pay a state visit to Britain.
But Bush has visited the country before and had lunch at Buckingham Palace with Queen Elizabeth II in July 2001.
So what's the difference between a state visit and other official visits? CNN placed a call to Buckingham Palace to find out.
"That's quite a difficult question," a palace spokeswoman said. "There is no clear cut definition. I guess we would define it as banqueting with the queen.
"I know lots of presidents have done that in the past, but there's usually a carriage procession, a lot more ceremonial, usually the queen greeting the guest, a bit like when Russia's President Putin was here, there was a procession in carriages. And staying at a royal residence."
But U.S. President Ronald Reagan and first lady Nancy Reagan stayed with the queen in Windsor Castle, a stone's throw from west London's Heathrow Airport, as official guests, the British monarchy's Web site says.
The Reagans had a "magnificent state banquet," and the president went riding with the queen in Windsor Home Park. Reagan even addressed members of both Houses of Parliament at the Palace of Westminster.
Wondering whether the response from Buckingham Palace was the full picture, another call was placed to Robert Jobson, CNN's royal commentator.
"It's an invitation from one head of state to another. Of course this means her majesty's ministers (in the shape of Prime Minister Tony Blair) and the Foreign Office would have been consulted," Jobson said.
So a final call to the British Foreign Office. Same question.
"It's quite difficult to draw a difference, but the technical difference is a higher ceremonial content," a Foreign Office spokesman said. "This visit will cement and mark the closeness of this relationship, a very long-standing relation."
Bush is the 11th U.S. president to have taken office during the queen's reign, which began in February 1952 when Harry S Truman lived in the White House.
Other U.S. presidents who have visited Britain include Bush's father, George Bush, who had lunch with the queen and the Duke of Edinburgh in June 1989, and Bill Clinton, who visited the queen in December 2000.
The queen and the Duke of Edinburgh have made three state visits to the United States -- in 1957, 1976 and 1991. The pair also made an official visit to the U.S. West Coast in February 1983.
Woodrow Wilson was the first U.S. president to stay at Buckingham Palace, with King George V in December 1918.
"But never before have these visits been described as state visits, due to a preferred lower-key ceremonial program," the monarchy's Web site says.