President Obama has pledged to make the US economy his top priority
President Barack Obama is to meet the Queen for the first time in April, the BBC understands.
The private visit is due to take place at Buckingham Palace when the president visits Britain to attend the G20 London economic summit.
World leaders are meeting at the G20 in London on 2 April to discuss plans to tackle the current economic crisis.
The Queen's last meeting with a US president was with George Bush during his farewell European tour last June.
The BBC's royal correspondent, Peter Hunt, said: "This will be a brief but striking encounter between an American president who'll have been in power for some 70 days and a British monarch who has lived through the Second World War, the Cold War and the current terrorist threat.
'Winked at the Queen'
"The image of the two of them together is likely to be an iconic one. Rather like her prime ministers, the Queen has seen US presidents come and go.
"She met Barack Obama's predecessor four times, including at the White House during a state visit in 2007. It was a novel experience for her. When George Bush slipped up during a speech - he winked at the Queen."
The G20 is a group of the world's most powerful countries that together represent 85% of the world's economy.
On taking office Mr Obama pledged to make reviving the US economy his top priority.
The president's first budget predicted a deficit of $1.75tn - in real terms the highest level it has been since the Second World War.
Mr Obama has spoken of the hard choices that lie ahead for America and the budget noted that the new administration inherited a legacy of misplaced priorities from its predecessors.
The G20 includes both major industrial powers such as the US and Germany, and emerging economic powers such as Brazil and China.
The UK government, which holds the rotating presidency of the G20, has called a meeting in London to tackle the growing economic crisis.