The quartet summit on video with attendance of Turkish President Erdogan, French President Macron, German Chancellor Merkel and British PM Johnson also discussed possible joint measures against global coronavirus outbreak.
Turkish, German, British and French leaders on Tuesday discussed the Syria crisis and refugee issue as well as joint action against coronavirus in a video conference.
Turkish President Recep Tayyip Erdogan, French President Emmanuel Macron, German Chancellor Angela Merkel and British Prime Minister Boris Johnson also discussed methods of humanitarian aid to Syria's northwestern Idlib province.
"We found opportunity to extensively evaluate many topics ranging from fight against coronavirus and the humanitarian situation in [Syria’s] Idlib, to solutions to Syria crisis, matter of asylum seekers and Turkey-EU relations at the summit," Erdogan said on Twitter following the summit.
"In this difficult process that we pass through at the regional and global level, we will operate diplomacy and cooperation mechanisms more actively, and we will resolutely continue our efforts to resolve problems as soon as possible," he added.
Germany promises assistance
Speaking to reporters in Berlin, Merkel said, "Germany has earmarked €25 million [$27,498] plus €100 million [$109,994] for humanitarian assistance, and this must now quickly reach to the people,” she said, referring to millions of displaced Syrians who moved near Turkish border due to intense attacks by the Assad regime in recent months.
"We have expressed our willingness to offer more financial support if necessary," she said, adding that they were also aware of Ankara’s expectations for upgrading the EU-Turkey Customs Union.
The European Union has called on Turkey to stop refugees and migrants, from Afghanistan, Pakistan and Africa as well as Syria, trying to cross the border.
Greece has used tear gas and water cannons against the refugees and migrants, and both countries have sent troops or security forces to the border.
Ankara has accused Greek forces of shooting dead four refugees at the border, a claim Athens denies.
Action against coronavirus
The talks were originally planned as a summit meeting in Istanbul.
That was changed after the spread of coronavirus prompted all four countries to impose travel restrictions.
Leaders agreed to work jointly to combat the virus.
Ankara is accusing the EU of not keeping its promises over 2016 deal while Turkey has reduced refugee flows to the EU by 97 percent, the Europeans have dragged their feet on financial commitments towards refugees and on resettlement.
The EU failed to keep its promise that pledged $6.8 billion in aid to finance projects for Syrian refugees in Turkey.
The summit also discussed Syria's northwestern province of Idlib, where a nearly two-week-old ceasefire struck by Russia and Turkey is broadly holding.
Erdogan has repeatedly said the European Union and NATO have to support Turkey to protect civilians there.