"The EU cannot accept this blackmail. Turkish efforts to welcome in Syrian refugees cannot then become a tool of blackmail for a military initiative that we cannot accept and which must immediately stop," Conte told reporters.

Turkey, which still formally aspires to join the European Union despite mounting EU criticism of Ankara's human rights record, has been stung by EU criticism of its air and land offensive against formerly U.S.-backed Syrian Kurdish fighters.

In a speech on Thursday, Turkish President Tayyip Erdogan told the European Union to "pull itself together" and threatened that if the bloc labeled the operation an occupation he would "open the gates and send 3.6 million refugees" to Europe.

ROME - The European Union must not bow to threats from Turkey to push millions of Syrian refugees into EU countries, Italian Prime Minister Giuseppe Conte said on Friday, adding that Ankara should stop its military operations in northern Syria at once.