In his speech, Cameron said Britain should be able to take back some of the powers now held by the European Union, The Guardian reported. He also said his country would like to opt out of the promise of an "ever-closer union" in the 1957 Treaty of Rome, the founding document of the European Economic Community.
Cameron was scheduled to deliver the speech last week but postponed it because of the Algerian hostage crisis. As expected, he said Britain will renegotiate the terms of its EU membership after the 2015 election, assuming he remains prime minister, and then hold a referendum vote in 2018.
"We understand and respect the right of others to maintain their commitment to this goal," he said. "But for Britain -- and perhaps for others -- it is not the objective. And we would be much more comfortable if the treaty specifically said so, freeing those who want to go further, faster, to do so, without being held back by the others."
Merkel said she and her country want Britain to be "an active member of the European Union."
"We are prepared to talk about British wishes but we must always bear in mind that other countries have different wishes and we must find a fair compromise. We will talk intensively with Britain about its individual ideas but that has some time over the months ahead," she said.
The Czech prime minister was the only European leader to back Cameron. French President Francois Hollande said Britain could vote to stay in or leave the union but cannot use a referendum to change the terms of membership.