LUXEMBOURG: EU foreign ministers on Monday discussed cracking down on Belarus's state airline in a bid to curb the flow of migrants that the bloc says Minsk is sending over its borders.

German Foreign Minister Heiko Maas called Belarusian President Alexander Lukashenko "the boss of a state-organised human smuggling ring" as he pushed for fresh sanctions at a meeting in Luxembourg.

"We are no longer willing to watch companies such as airlines earning money by bringing refugees," Maas said.

"We need sanctions to underline that we cannot tolerate this any longer."

The EU accuses the Belarusian authorities of funnelling migrants from the Middle East and Africa towards the bloc in retaliation for sanctions imposed on Minsk over its crackdown on the opposition.

The EU's Baltic members are pushing to stop the leasing of planes to Belarusian state carrier Belavia as part of a new package of sanctions being drawn up in Brussels.

But Ireland - a key hub for aircraft leasing companies in the bloc - warned that it may prove difficult to sever contracts already in place.

"Where there are existing contracts we're not sure how that can be unwound legally, but what certainly we're saying is that that there should be no future contracts," Irish Foreign Minister Simon Coveney said.

EU foreign policy chief Josep Borrell said that "more measures are needed, certainly but let us see what the member states decide".