Turkish President Recep Tayyip Erdogan on Thursday threatened to reopen a route for Syrian refugees to reach Europe if it does not receive more support for a a resettlement plan centered on northern Syria.
Erdogan has urged the US to take further action on establishing a safe zone in northeast Syria, where Washington has a military presence in support of a Kurdish-led force fighting the "Islamic State" militant group.
"This either happens or otherwise we will have to open the gates," said Erdogan.
"Either you will provide support, or excuse us, but we are not going to carry this weight alone. We have not been able to get help from the international community, namely the European Union."
In 2016, the EU made a deal with Turkey that effectively closed the so-called Balkan route, once considered the main pathway for hundreds of thousands of refugees fleeing war in Syria.
In exchange for blocking migrants from crossing into Greece, the EU offered Turkey €6 billion ($6.6 billion) and the chance to speed up EU accession talks. "To date the EU has provided €5.6 billion out of the €6 billion that was agreed," said EU migration spokeswoman Natasha Bertraud.