The European debt crisis is adding to the uncertainty looming over the global economy and must be tackled swiftly, British Prime Minister David Cameron has warned, dpa reported. In a speech to the Canadian parliament in Ottawa late Thursday, Prime Minister David Cameron called on European nations to show that they had the "political will to do what is necessary." "One way or another, they have to find a fundamental and lasting solution to the heart of the problem - the high level of indebtedness in many Euro countries," said Cameron. "Endlessly putting off what has to be done doesn't help, in fact it makes the problem worse, lengthening the shadows of uncertainty that looms over the world economy," he added. -- SPA