ANTALYA: Leaders from the world’s top 20 industrial powers meet in Turkey from Sunday seeking to overcome differences on a range of issues including the Syria conflict, the refugee crisis and climate change.

With the health of the global economy less of a headache than in previous years, it is the war in Syria that will cast the longest shadow at the two-day Group of 20 summit in the Mediterranean resort of Antalya.

Security will be tight even by the draconian standards of previous such meetings, with some 12,000 police on duty and the authorities conducting raids in search of Daesh militants who have slipped over the border from Syria.

The meeting is the biggest gathering of world leaders ever hosted by Turkey and gives President Recep Tayyip Erdogan the perfect opportunity to present himself as a key global player two weeks after his party regained its overall majority in a parliamentary election.

“I pray and hope that G-20 will provide a platform whereby all of these issues can be discussed openly and then we can understand each other,” Erdogan told CNN ahead of the summit.

But finding agreement on Syria will be tough, with Russia vehemently opposed to host Turkey’s strategic aim of toppling Bashar Assad and Ankara so far only receiving a lukewarm response to its plan of a safe zone inside Syria.

“A breakthrough is very unlikely on Syria or the refugee question,” said Ozgur Unluhisarcikli, Ankara office director for the German Marshall Fund of the United States.

At the same time, he said the G-20 would make a show of unity on the aim of bringing peace to Syria in the final communique. “They will want to end on a positive note, on a convergence of strategy.”

A German official said five working sessions were expected to discuss development and climate change, economic growth, financial markets and reforms as well as global challenges such as terrorism and refugees.

The source said the refugee issue was expected to be raised specifically at the leaders’ dinner on Sunday night.

Turkey, which is hosting 2.2 million refugees from Syria, wants a concrete financial aid package from Europe in return for stemming the flow of migrants setting out from its shores to Europe.

“It’s very difficult (on refugees) as the positions are very different from each other... though there will be a certain level of lip service on both sides,” said Unluhisarcikli.

Sources said the final communique was expected to mention refugees, even if some countries did not see the G-20 as the right forum for the discussion.