Hungary's prime minister has said the country is filing a lawsuit against the European Union objecting to a mandatory plan to distribute migrants among members of the bloc.
Viktor Orban said the suit would be filed at the European Court of Justice. The EU is looking redistribute 120,000 asylum seekers already in the bloc among its 28 countries.
Parliament last month approved legislation obliging the government to challenge the EU quotas, while Mr Orban has repeatedly said that Brussels overstepped its authority when it approved the scheme despite opposition from a handful of mainly Eastern European countries.
Mr Orban earlier also described the migrant quotas as "illegal, unreasonable and unfair" and said it was wrong to force countries to take in migrants against their will.
Robert Fico, the prime minister of neighbouring Slovakia, said that his country had filed its own complaint against the EU quotas.
Meanwhile, a t least two people have been injured during clashes between groups of migrants and refugees on the Greek-Macedonian border.
A man believed to be from Morocco died after touching high-power overhead railway cables when he climbed on top of a train carriage.
Macedonia is allowing only people from Afghanistan, Iraq and Syria to cross the border, and groups of people from other nationalities have set up makeshift roadblocks, preventing anyone from crossing.
And Greek authorities said they have recovered the body of a woman and are still searching for three other missing migrants after their small boat sank in the eastern Aegean Sea.
The boat was carrying a total of seven migrants, and the coast guard said three survivors were pulled from the sea after Thursday's capsizing off the island of Farmakonissi. The nationalities of the migrants were not immediately known.
Greece is at the forefront of Europe's immigration crisis, with more than 700,000 people having crossed over so far this year from nearby Turkey. Hundreds have drowned in the effort.