European Council President Donald Tusk warned lawmakers in Strasbourg on Tuesday of a possible new wave of refugees if Bashar al Assad wins the civil war in Syria.
Tusk, citing Turkish President Recep Tayyip Erdogan, said an influx of three million refugees could be result from a “potential victory” of the Assad regime.
"A potential victory of Assad's regime, is more likely today because of Iran and Russia's engagement in Syria, and will result in the next migratory wave," Tusk said. "Yesterday, this message was confirmed by President [Recep Tayyip] Erdogan. According to Turkish estimates, another 3 million potential refugees may come from Aleppo and its neighbourhoods," he added.
President Erdogan visited Donald Tusk, President of the European Commission Jean-Claude Juncker, and President of the European Parliament Martin Schultz on Monday to talk about refugee crisis, calling for measures to combat the militant groups and to give new life to Turkey's EU membership bid.
Since the beginning of civil war in Syria Turkey has spent up to $8 billion on hosting almost two million refugees.
Tusk has criticized some EU member countries such as Hungary Italy, Slovakia and Greece for failing to fully respect EU asylum and border rules, and called for unity and solidarity between EU member countries.
"We keep talking about solidarity, about quotas and greater assistance for refugees on our soil, and for those who remain in camps and countries outside the EU. Let's remember, however, that solidarity requires mutual understanding and respect," he said.
Tusk also added, "We have to respect commonly agreed rules... It is our common obligation to assist refugees as well as to protect the EU's external borders."
Hungary has built a 75 kilometer long and four metrer high razor wire fence along its border with Serbia intended halt the refugee influx, and has closed railway links with Serbia.
Tusk highlighted the importance of controlling the EU borders by saying, "The first commandment today is restoration of control on the EU external borders as condition sine qua non of an effective, humanitarian and safe migratory policy."
Leader of the European Liberals and Democrats Guy Verhofstadt called for an immediate European initiative to end the ongoing conflict and voiced support for the installation of a no-fly zone in Syria.
"Council President Tusk's and High Representative [Federica] Mogherini's priority must be to negotiate a common European position to defeat IS [ISIS] and get rid of Assad... The EU should support an immediate installation of a no-fly zone in Syria," Verhofstadt said.
Jean-Claude Juncker underlined that cooperation with Turkey was essential to halt the refugee crisis.
"Turkey and the European Union need to walk together [down] this path. We need to look at providing help to those unfortunate people who come to our shores," he said.
He also called attention to the European Parliament's role in resolving the refugee crisis, "The European Parliament's given its green light for a fair distribution of refugees, which has really forced the hand of the Council to do the same thing. (...) So I am extremely grateful to you, President, and to the members of this Parliament for having reacted so quickly, something I think really characterises this Parliament."
Juncker added that a joint EU-Turkey action plan addressing the refugee crisis would be revealed on Tuesday.
The EU pledged one billion euros last month for Syrian refugees in Turkey, Jordan, Lebanon and other countries.