British Prime Minister David Cameron arrives to attend an European Union (EU) emergency summit on the migration crisis at EU Headquarters in Brussels, Belgium, Sept. 23, 2015. [Xinhua]

Leaders of European Union (EU) member states gather in Brussels Wednesday afternoon for an informal summit to discuss an overall approach to the refugee crisis and the necessity to establish a credible European migration policy.

The summit, which was proposed by European Council President Donald Tusk, was slated for Wednesday evening.

"Today, our debate must be based on facts, not illusions and emotions," said Tusk in his doorstep remarks, noting that there are eight million displaced people within Syria, while about four million have fled from Syria's to Turkey, Lebanon, Jordan and Iraq.

"This means that today we are talking about millions of potential refugees trying to reach Europe, not thousands," he said.

"After my visits to Turkey, Jordan, Egypt and other countries in the region, I realized that our partners are expecting our help to solve their refugee problems rather than thinking of how they can help us. It is likely that more refugees towards Europe will flow through their countries, not less," Tusk said.

He said that "the most urgent question people should ask ourselves tonight is how to regain control of our external borders," otherwise it does not make sense to even speak of a common European migration policy.

British Prime Minister David Cameron said upon his arrival "We will be taking further actions today, what Europe needs more than ever is comprehensive approach to this migration crisis," noting that people need to stabilize the countries and regions from which the refugees are coming.

When it comes to Syria, Cameron said Britain had already given over 1 billion pounds (1.53 billion U.S. dollars), more than any other country, other than the United States.

He announced that Britain will commit another 100 million pounds, including 40 million pounds to the vital world food program.

"We must make sure the people in refugee camps are properly fed or looked after, not least help them, but also stop people wanting to make or thinking of making this very very difficult and very dangerous journey," he said.

Greek Prime Minister Alexis Tsipras said that an united Europe means first of all sharing, calling for sharing of "responsibility, burden and capability, and common future".

In Tusk's invitation letter, he also appealed to EU leaders to urgently provide financial donations to the World Food Program for food support to the 11 million people in Syria and in the region.

During the summit, the EU leaders will also discuss issues including help to frontline member states, cooperation with Western Balkan countries, Turkey and countries bordering Syria, financial assistance to the High Commissioner for Refugees and the World Food Program return and readmission, and diplomatic efforts to solve the crisis in Syria.

The summit followed a home affairs ministers' meeting in Brussels, during which EU member states approved European Commission's proposal to relocate 120,000 migrants by a majority vote on Tuesday. The latest agreement made the total relocation quota within the EU amount to 160,000.

Slovak Prime Minister Robert Fico said earlier Wednesday that Slovakia opposes quotas for reallocating refugees among EU members and will file a lawsuit with the EU General Court in Luxembourg concerning the way in which the move was adopted. (1 pound = 1.53 U.S. dollars)