The leaders of Germany and Great Britain met on Thursday, eager to push their message of closer collaboration by European leaders as the continent struggles to overcome its debt crisis.

German Chancellor Angela Merkel called for countries to give up more powers to Europe "step by step" and says a "political union" is needed.

"We need not just a currency union; we also need a so-called fiscal union, more common budget policies. And we need above all a political union," Merkel said.

"We must, step by step ... give up powers to Europe as well," she said.

Merkel was meeting with her British counterpart David Cameron in Berlin Thursday. For his part, the British leader echoed Merkel's call for action.

"Speed is of the essence," he said late Wednesday ahead of the meeting. "Clearly the euro zone crisis is the biggest threat to the world economy today," he added.

Cameron is pressing for euro zone countries to protect their currency with measures including greater fiscal burden-sharing among member countries.

With files from The Associated Press