According to a statement from Cameron's office, the UK prime minister said he wanted to land a deal on four key reforms with his fellow EU leaders at next month's European Council summit.

"On the UK renegotiation, they agreed that there had been progress since December's European Council and that there was genuine good will across the EU to address the British people's concerns in all four areas," said the statement.

"Both concluded that there was more work to do ahead of the February European Council to find the right solutions."

The two leaders, who spoke by phone on Monday, also said a strong external European border was vital to dealing with the ongoing migrant crisis.

Cameron has promised British voters an in/out referendum on EU membership by the end of 2017. He's vowed to secure reform and campaign for the UK to remain in the 28-nation bloc.

The vote could be held as early as June, amid realistic worries of a British exit, or Brexit. Previously, Germany has said the UK's exit from the EU would be a "disaster."

Fair deal for the UK?

Cameron has highlighted economic governance, competitiveness, immigration and sovereignty as key areas for reform in the EU.

As Brussels moves towards a greater financial union, London wants to ensure that those countries remaining outside the eurozone are not disadvantaged.

Cameron has also lobbied for tougher social security criteria for new migrants to the UK coming from within the EU, who would only receive welfare after four years.

London is also against greater political union and seeks increased powers to block EU legislation, when required.

Polls are giving mixed signals about voters' willingness to stay part of the EU. Last week, an ORB poll for "The Independent" newspaper found 52 percent believe Britain should remain in the EU. But similar surveys have shown a majority of voters desire a Brexit.

EU leaders are due to hold the next European Council summit on February 18 and 19.

mm/cmk (AFP, Reuters)