London  - Barack and Michelle Obama went to Buckingham Palace to have tea with Queen Elizabeth II Wednesday after the US President declared himself to be a fan of the 82-year-old monarch.

"There is one thing I should mention that I love about Great Britain and that's the queen," said the 47-year-old President hours before his armour-plated limousine pulled up at the palace.

"I think in the imagination of people throughout America, what the queen stands for, her decency and her civility and what she represents is very important."

The warm words will have been music to the ears of Britain's royal family, often portrayed at home and abroad as an institution out of touch with modern times.

The Obamas, representing the same generation as the queen's own children, certainly brought a flair of modernity and excitement to the royal palace.

As the presidential motorcade rolled up, the BBC played "You'll be my American Boy, American Boy," by US singer Estelle.

Michelle Obama, wearing a dramatic monochrome outfit of a full black skirt, white scoop-neck top and flowing black satin coat, said "Hi" and Hello" as she entered the palace with her husband.

The queen, wearing a bright salmon pink dress, smiled warmly as she shook hands with the US couple, who were towering over the much smaller monarch.

She listended attentively to the US President's account of his high-profile political meetings with world leaders during the day - crowned by the palace reception.

Hundreds of curious onlookers waited behind barriers in the evening sunshine to see the couple arrive, with adults and children taking snapshots of the bullet-proof limousine, known as the Beast.

"She is a lovely lady, she can talk to anyone," said a British woman who had watched Michelle Obama during an earlier visit to the cancer unit off a London hospital.

After their relaxed 20-minute chat on sofas in the palace's private rooms, the couple emerged smiling to pose for a photograph with the queen, and her husband, 87-year-old Prince Philip.

During the queen's 57-year reign there have been 12 US presidents. With the exception of Lyndon B Johnson, she has met them all.

But even for someone as skilled and experienced as the queen - when it comes to protocol and entertaining - the evening proved testing.

For while she had her chat with the Obamas, limousines carrying heads of states and governments from around the world pulled up at short intervals at the palace for a reception of G20 participants.

Guests at the royal event included the leaders of Russia, India, Saudi Arabia, Brazil and China, as well as Ban Ki-moon, the head of the United Nations.

Palace staff served canapes, wine, Champagne and soft drinks as the monarch mingled among her guests, making sure that she exchanged a few words with each one of them before her array of colourful guests bid their courteous farewells. (dpa)