David Cameron congratulates Barack Obama on re-election victory
Prime Minister David Cameron has sent his congratulations to Barack Obama, who has been re-elected to a second term as US president.
"I think he's a very successful US president and I look forward to working with him in the future," he said.
Labour leader Ed Miliband said Mr Obama's victory was built on creating a "fairer economy".
Mr Obama saw off a hard-fought challenge from Republican candidate Mitt Romney.
Speaking during a tour of the Middle East, the prime minister said: "I would like to congratulate Barack Obama on his re-election.
"I have really enjoyed working with him over the last few years and I look forward to working with him again over the next four years.
"There are so many things that we need to do: we need to kick start the world economy and I want to see an EU-US trade deal.
"Right here in Jordan I am hearing appalling stories about what has happened inside Syria so one of the first things I want to talk to Barack about is how we must do more to try and solve this crisis.
"Above all, congratulations to Barack. I've enjoyed working with him, I think he's a very successful US president and I look forward to working with him in the future."
Foreign Secretary William Hague said he was looking forward to working with President Obama and his team on "shared foreign policy goals".
Mr Miliband offered his own congratulations, tweeting: "Great victory based on building fairer economy and optimism about what politics can achieve."
Deputy prime minister Nick Clegg sought to draw a parallel with domestic politics, suggesting Mr Obama's victory showed voters had "long memories" when it came to those they believed were responsible for the current economic difficulties.
"When it comes to actually casting a vote, voters remember who created the mess in the first place and who has to do the painstaking, difficult and, longer-than-we-had-hoped, job of clearing up that mess," the Lib Dem leader - standing in for Mr Cameron at prime minister's questions - told MPs.
As well as co-operation over trade, Mr Clegg said he wanted the US and Europe to work closer together on tackling the effects of climate change.
Conservative MP John Redwood suggested there would be "rejoicing" in the UK at Mr Obama's victory since there was a feeling across Europe he would be "more caring, more friendly to the rest of the world than Mr Romney would be".
But he said the president had serious questions to answer over his economic strategy and the war in Afghanistan.
"Now what matters is how he tries to heal the raw feelings of disagreement in his country, and how he starts to tackle the debt mountain and deficit he has created," he wrote on his blog.
Conservative MP Rob Wilson said the outcome of Tuesday's election suggested the US was "in for a difficult four years".
"A split country and Obama looks like he might be a lame duck president," he wrote on Twitter.
But Conservative colleague Guy Opperman said Mr Romney's defeat showed he had failed to capture the "middle ground".
"Mitt Romney clearly did not win because he lurched to the right," he told the BBC. "He was taken over, to a certain degree, by the Tea Party, particularly during the primary campaign and was not able to occupy the middle ground.
"Because he could not get to the middle ground and could not occupy what most people want on a centrist, centre-right point of view, he lost that core support...that he needed to win the election."