The UN Security Council will hold an emergency meeting Thursday on the migrant crisis at the border between Poland and Belarus, diplomats said.

Several thousand migrants who want to access the European Union are stuck along the forested border between Poland and Belarus, which is allied with Russia.

With Poland accusing Belarus of "state terrorism," the 15-member council will meet behind closed doors for a session called by Estonia, France and Ireland, diplomats said Wednesday.

Concern was growing for more than 2,000 migrants -- mainly Kurds from the Middle East -- who are trapped at the border, with the UN calling their plight "intolerable" and demanding action.

Western governments accuse Belarusian strongman Alexander Lukashenko of luring them to his country and sending them to cross into Poland in retaliation for sanctions.

"Such situations should not be used for political purposes and become a cause of tension between states," UN spokesman Stephane Dujarric said Wednesday.

"The secretary general is following with concern the situation in the Belarus Poland border. He reiterates the importance of ensuring that migration and refugee issues are dealt with according to humanitarian principles and international law."