Hungary is ready to sue the European Commission to reimburse the costs of protecting the European Union's external border, which Budapest says has cost it some 2 billion euros , Prime Minister Viktor Orban's chief of staff said.
Nationalist Orban closed down a major transit route through Hungary for hundreds of thousands of asylum seekers fleeing war and poverty in 2015, bolstering his support at home but earning him widespread criticism from many EU allies.
Orban has displayed a sense of vindication after Germany on Monday announced plans to impose tighter checks at all of its land borders in what it called an attempt to tackle irregular migration.
The controls within what is normally a wide area of free movement - the European Schengen zone - will start on Sept. 16 and initially last for six months in a shift from Berlin's previous open-door policy.