The EU yesterday stepped up warnings that countries could be punished if they fail to share the burden of mainly Syrian refugees stranded in Greece and Italy.

Migration Commissioner Dimitris Avramopoulos said member states had until September to take in 160,000 Syrian and other refugees from the two countries, which have been on the frontline of the migration crisis.

So far only 13,500 have been relocated in a process bogged down by general inertia and resistance from Eastern European states which oppose Muslim immigration.

"If we don't have tangible efforts by September... the commission will not hesitate to make use of its power," Avramopoulos, who is Greece's EU commissioner, told a news conference.

The EU has been trying to convince members states "to do their duty," he said.

■ But if it is not the case in the future, infringements might be an option," he said.

As the executive branch of the 28-nation EU, the European Commission is able to launch "infringement proceedings" to impose fines on member state that break the bloc's rules.

Countries like Hungary and Slovakia have proposed paying "solidarity" contributions instead of actually taking in any migrants.