British Prime Minister David Cameron has sent his congratulations to Barack Obama, who has been re-elected to a second term as U.S. president, BBC News reports.

"I think he's a very successful U.S. president and I look forward to working with him in the future," he said.

Labor leader Ed Miliband Obama's victory was built on creating a "fairer economy".

Obama saw off a hard-fought challenge from Republican candidate Mitt Romney.

Speaking during a tour of the Middle East, Cameron 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-U.S. 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 U.S. 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".

Miliband offered his own congratulations, tweeting: "Great victory based on building fairer economy and optimism about what politics can achieve."

But Conservative MP Rob Wilson said the result suggested the U.S. 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.