Macedonia's president says neighboring Greece is not being cooperative on the immigration crisis following a large influx of refugees into his country on Monday.

Gjorge Ivanov convened a meeting of the National Security Council late Tuesday, and afterward told the press that Greece should stop allowing migrants to reach the boundary between the two nations.

About 14,000 people are stuck in a muddy tent city at the Idomeni crossing, on the Greek side of the border, hoping that Macedonia will allow them through on their journey to Europe's prosperous heartland.

About 1,500 bypassed a fence Monday to enter Macedonia, but were detained and forced back into Greece — with violence according to some refugees. Macedonia has rejected the claims.

Ivanov called for better cooperation between Macedonian and Greek security services.