Slovakia filed a lawsuit at the European Court of Justice on Wednesday against the European Union’s quota decision to redistribute refugees among member countries as the first legal challenge.
"The Slovak Republic has officially filed a lawsuit against the Council of the European Union, to the highest court ... in Luxembourg," Prime Minister Robert Fico said.
The lawsuit challenges the "so-called mandatory quotas," he added.
So far this year, nearly 890,000 refugees have reached European shores, which is about four times the total in 2014, according to United Nations.
In late September, European Union leaders - France and Germany weighting - agreed to share 160,000 refugees across the bloc, outvoting four eastern European countries - the Czech Republic, Hungary, Poland and Slovakia - who strongly opposed the arrangement.
Under the EU's quota system, Slovakia is expected to take in just under 2,300 refugees.
"We demand that the court rules the decision on imposing mandatory quotas is invalid," Fico told reporters on Wednesday.
"I consider the quotas to be nonsensical and technically impossible. Our words are being proven true, the quotas have become a fiasco."
Few refugees entered Europe through Slovakia and even less - 154 - applied for asylum.
Hungary also said it will challenge the quota restriction.
Hungarian Prime Minister Viktor Orban claimed on Wednesday that EU and Turkey could announce an agreement within days to resettle some half a million Syrian refugees directly from Turkey to the EU.
“This nasty surprise still awaits Europeans. My assumption is that such an unofficial agreement exists,” Orban said.
He said he expects intense pressure from Europe on Slovakia, the Czech Republic, Hungary and Poland.
“This pressure will define the politics of Europe in the coming days. It will not be an easy one because obviously we cannot accept it like this," he added.
The Czechs and Romanians have said they will not sue.