Hungary's prime minister says he believes a secret pact led by Germany to bring up to 500,000 Syrians from Turkey directly into the European Union will be revealed soon.

Viktor Orban said Wednesday that a similar idea was rejected recently by European national leaders but that "the cat will be out of the bag" and the scheme will be announced in Berlin as soon as this week.

Orban says "this secret agreement exists and we will be confronted by it in the coming days."

He says the plan includes forcing all EU countries to take in some migrants, even if they are opposed to mandatory quotas.

Orban said there will be "huge pressure" on countries like Hungary and others to take part.

Greece's migration minister, meanwhile, says his country has come under "intense pressure" from some European countries over the migration crisis, but he says that's unfair.

Reacting to a story in the Financial Times, Ioannis Mouzalas told reporters Wednesday that no official threat has been made to eject Greece from Europe's borderless Schengen area. He says accusations by unidentified European officials in the FT story were a mixture of "reality and myth."

Greece has been the main point of entry into the EU for about 700,000 migrants and refugees so far this year.

Mouzalas says: "It's true that our country has come under intense pressure from some European Union member countries who mistakenly believe that the refugee flow can be controlled from Greece. As we've repeatedly stated and as Europe has belatedly understood, Greece is the start of the corridor. The door is in Turkey. Therefore if the flows are not controlled in Turkey, from the coast of Turkey, it is impossible to control the flows from Greece or any other European Union member."