Turkey is keeping the high-tension tightrope taut on its northern land border with Greece along the Evros River, indicating it may yet again send there migrants it's been holding in an attempt to get them to cross, as well as to Greek islands.

The last time that happened, in late February, some 10,000 were taken there but Greece closed its side and sent riot police and Army units there to repel them, leading to exchanges of teargas and with Turkey claiming one migrant was shot dead.

Turkey has also been letting human traffickers keeping sending refugees and migrants to five Greek islands near its coast, in constant violation of an essentially-suspended 2016 swap deal with the European Union.

Turkey is holding about 5.5 million of them, people who fled their homelands and war and strife, especially Afghanistan and Syria's civil war, and is supposed to contain them in return for EU aid but said some 3 billion euros ($3.24 billion) has been withheld.

As his country has kept up violations of Greek airspace, sending in waves of F-16 fighter jets intercepted by Greek pilots, Turkish Foreign Minister Mevlut Cavusoglu said  there's an “open border” policy that will let migrants and refugees now leave.

On Turkey’s Akit TV, Cavusoglu also denounced what he described as Greece’s “inhumane” behavior toward migrants seeking to cross into the country without explaining why Greece can't enforce its sovereign rights.

That raised new worries in Greece, which has been beefing up defense along the Evros River, expecting another surge by land and possibly migrants trying to cross the treacherous water passage that has claimed many lives over the last four years.

The National Council on Foreign Policy under Foreign Minister Nikos Dendias met to talk about Turkey’s aggressive behavior as well as diplomatic initiatives by Greece, all of which have failed as Turkish President Recep Tayyip Erdogan has become more belligerent with the EU not issuing sanctions and NATO, the defense alliance to which both countries belong, refusing to intervene over the unstopped Turkish violations.