British Prime Minister David Cameron and European Council President Donald Tusk will meet Sunday to try to hammer out a deal aimed at keeping the U.K. in the EU, after Cameron said the existing proposal is "not good enough."

The two men will hold talks over dinner at 10 Downing St., with Cameron due to demand stronger powers to curb British welfare benefits to migrants from other EU countries.

Officials hope to strike deal on Feb. 18-19. If he gets enough reform, Cameron will urge British voters to back continued EU membership in a referendum that must be held by next year and could come as early as this summer.

Before the meeting, Tusk tweeted that he would "present solutions" to all of Britain's main areas of concern. He said agreement must be acceptable to all 28 EU members, with "no compromise on fundamental freedoms."

The 28-nation bloc allows citizens to work and live freely among member nations - but Britain's Conservative government says hundreds of thousands of people from Eastern Europe who have flocked to the U.K. are straining schools, hospitals and social services.

Welfare benefits have become the key issue, and main sticking point, in Britain's negotiations with the rest of the EU.

On Friday top EU officials offered Britain a mechanism known as an "emergency brake" that would let the U.K. temporarily limit benefits to immigrants if the country's welfare system comes under strain.

The proposal could satisfy Britain's goal of regaining some control over immigration and other countries' desire to maintain the principle of free movement.

Cameron said Friday that the proposal is "not good enough ... but we are making progress." He's likely to tell Tusk the "emergency brake" must take effect sooner and stay in place longer than the EU has proposed.

Britain also wants to see more power ceded from Brussels to national parliaments, a reduction in EU red tape and protection for the nine EU countries, including Britain, that do not use the euro single currency.