Buckingham Palace has confirmed US President Barack Obama will come to the UK on a state visit in May.

白金汉宫证实，美国总统奥巴马将于五月对英国进行国事访问。

Mr Cameron and Mr Obama met in London in 2008 before either man had been elected
It is the first state visit by a US president since that of President George W Bush and his wife, Laura, in 2003.

President Obama came to the UK for the G20 summit in 2009 but that was not a state visit.

In July last year David Cameron visited Washington and met Mr Obama, who will visit London from 24 to 26 May.

The First Lady, Michelle Obama, will accompany the president on the visit but details of his itinerary¹（路线，旅程） have not been announced.

The prime minister's official spokesman said on Thursday: "The prime minister is very pleased this visit is taking place. It is a sign of the strong and enduring relationship between our two countries."

Last year's meeting, which was dominated by recriminations（反责，揭丑） after the BP oil crisis in the Gulf² of Mexico, ended with President Obama describing the Anglo-American relationship as "truly special".

There are only usually one or two state visits a year to the UK and the last one was in October when the Emir of Qatar came to Britain.

A state visit is a formal affair when a visiting head of state is accorded full ceremonial trappings（服饰） and is hosted by the Queen.

She has met every US president since 1952 with one exception - Lyndon B Johnson.

State visits are formal visits to the UK by foreign heads of state "with the aim of strengthening Britain's relationships with other countries".

The Obamas will stay at either Buckingham Palace or Windsor Castle and the official welcome of state visit guests usually takes place on Horse Guards' Parade.

The Obamas will also attend a state banquet（国宴） in their honour.

White House spokesman Jay Carney said: "This will be the president's first European state visit, a sign of the strength of the relationship between our two countries and a sign of his enduring commitment to our European allies."