The European Union's commissioner for migration says there are ways to make all EU members states comply with the program of relocation of migrants among them.

Dimitris Avramopoulos made the statement Tuesday in Warsaw, where he is visiting the growing European border guard agency, Frontex.

Poland is refusing to accept migrants, arguing they are chiefly economic migrants, not war refugees, and may potentially pose a threat.

The relocation plan is intended to ease the pressure on countries that have taken the brunt of the migrant wave: Italy and Greece.

Without naming Poland, Avramopoulos said the EU has the "tools, the means and the power" to convince all members to comply and will make an assessment of response by the end of September. He mentioned no sanctions.