ORESTIADA, Greece — Greece took a raft of tough measures Sunday as it tried to repel thousands of migrants amassed at its border with Turkey.

It deployed major military forces to the border, seeking to fortify the area after Turkey allowed migrants to pass through to the European Union over the weekend. The Greek government also said it would suspend asylum applications for a month and summarily deport migrants entering illegally.

The developments were increasing tensions between the two countries, leaving thousands of people exposed to winter weather and caught in an increasingly volatile situation.

Neither move announced by Greece is permitted by European Union law, but the Greek government said it would request special dispensation from the bloc. International protocols on the protection of refugees, of which Greece is a signatory, also prohibit such policies.