Turkish President Recep Tayyip Erdogan speaks to journalists in Istanbul, Turkey, Feb. 3, 2020. (Turkish Presidential Palace/Handout via Xinhua)

Turkish President Recep Tayyip Erdogan warned on Monday that "millions" of migrants would soon head for Europe, drawing accusations from EU leaders that he is trying to pressure them into backing his incursions into Syria.

Turkey gave the green light to refugees and migrants on Friday to leave for the EU and thousands have since massed at the Greek border, triggering fears of an influx like that which poisoned European politics in 2015.

German Chancellor Angela Merkel described Turkey's move as "unacceptable" and EU migration commissioner Margaritis Schinas said nobody could "blackmail or intimidate the EU."

But Turkey, which hosts roughly four million refugees, is trying to hold off another mass influx from Syria.

Erdogan further ramped up the pressure late on Monday, saying he had turned down an EU offer of one billion euros ($1.1 billion) in extra aid for migrants, adding to a six billion euro deal agreed in 2016.

"We don't want this money," Erdogan said at a news conference.

His office later added that he had spoken to Merkel over the phone and warned once again that Europe must take a "fair share of the burden" of dealing with migrants.

He claimed the numbers of migrants at the Greek border - who include Afghans, Syrians and Iraqis - were far higher than figures provided by officials and reporters at the scene, saying "hundreds of thousands" were already there.

Greece says some 10,000 people were barred from entering the country over the weekend. Clashes broke out as police fired tear gas at the refugees, who responded by lobbing rocks.

AFP