Slovak Prime Minister Robert Fico says the Central European country will file a lawsuit by December 18, challenging an EU planned quota system to distribute 120,000 asylum seekers among member countries.
Fico said Slovakia would meet the December 18 deadline at the European Court of Justice.
"We will take the legal action at a court in Luxembourg sooner, we will talk about it this week," Fico said in a televised debate on November 29.
Slovakia, the Czech Republic, Hungary, and Romania opposed the mandatory quotas for redistributing migrants from Italy and Greece, but were outvoted at a meeting of EU interior ministers in September.
The EU has struggled to find a common approach on how to deal with a surge in migrants and refugees fleeing conflict and poverty in the Middle East, Africa and Asia.