President Barack Obama told prime minister Gordon Brown yesterday he looked forward to strengthening the "special relationship" between the US and the UK, the White House said.
In their first phone conversation since Mr Obama became president, the two leaders discussed the situation in Gaza and "the necessity to make Afghanistan a top priority," the White House said in a statement.
"President Obama said he looked forward to continuing and strengthening the special relationship between our two countries," it said.
"He expressed his desire to work together to confront the global economic crisis and reiterated his hope to attend the G-20 Summit in London."
Mr Obama initiated the call, which a Downing Street spokesman described as friendly and substantive.
The traditional "special relationship" between the United States and Britain is under scrutiny with the change of US administrations. In the past, Britain and the United States have enjoyed close military and diplomatic ties over the invasion of Afghanistan and Iraq, with Britain sending thousands of troops to the fields of operation.
Relations were warm under former president George W. Bush and ex-prime minister Tony Blair, but Mr Obama is expected to concentrate his efforts on forging links in Asia and the Middle East.
The president spoke to a number of world leaders yesterday including Saudi King Abdullah and Canadian prime minister Stephen Harper.
Mr Obama plans to travel to Canada for his first foreign trip, which is a tradition for incoming US presidents.
Mr Obama is due to visit Britain in April where he is to attend a G20 meeting of the world's leading industrialised and emerging economies.