The prime minister, on a two-day visit to Washington, also said Europe was anxious to work more closely with the US.
"You now have the most pro-American European leadership in living memory. A leadership that wants to co-operate more closely together, in order to co-operate more closely with you.
The administration of George Bush, Obama's predecessor, had antagonised many European governments over issues such as the invasion of Iraq.
Brown also said the US could not be expected to revive to the world economy, which is facing its worst crisis in decades, on its own.
|Thousands have lost their jobs amid
a global economic crisis [GALLO/GETTY]
"So let us work together for the worldwide reduction of interest rates and a scale of stimulus round the world equal to the depth of the recession and the dimensions of the recovery we must make," he said.
However, Brown said there were lessons to be learnt from the economic crisis, particularly that the global financial system could spread problems as well as benefits.
"Today's financial institutions are so interwoven that a bad bank anywhere is a threat to good banks everywhere," he said.
"So should we succumb to a race to the bottom and a protectionism that history tells us that, in the end, protects no one? No. We should have the confidence that we can seize the opportunities ahead and make the future work for us."
The US decision to include a "Buy American" provision in its massive $787bn economic stimulus package, requiring public works and building projects funded by stimulus cash to use only US-made goods has caused concern in Europe and elsewhere.
Brown also announced that Queen Elizabeth II had given an honorary knighthood to Edward Kennedy, a Democratic senator and a key Obama ally, partly for his work in promoting peace in Northern Ireland.
The British leader was the fifth prime minister to address a joint session of congress, the last being Tony Blair in 2003.