An international court this week ordered Turkey to free an opposition politician, ruling his prolonged detention in Turkey was politically motivated and harmed pluralism. But Selahattin Demirtas remains behind bars after the country’s strongman leader, Recep Tayyip Erdogan, rebuffed the court, threatening a confrontation with Europe.

The European Court of Human Rights (ECHR) said keeping Demirtas in prison for two years during dozens of trials on terrorism charges violated three articles of the European Convention on Human Rights. Erdogan promptly shot back, saying Turkey was not obliged to implement the decision, even though it is a signatory to the treaty, which says the Strasbourg-based court’s rulings are binding.

The standoff cast a shadow over a visit to Ankara by top EU officials for talks on Turkey’s long-stalled application for membership, just as the government works to repair its frayed relationship with the bloc. In her first visit to Turkey in more than two years, EU’s foreign policy chief Frederica Mogherini criticized Demirtas’ detention and the ongoing arrests of journalists, academics and activists.

“We hope he [Demirtas] will be released shortly, and that similar cases will be dealt with soon,” she said at a tense press conference on Thursday with Turkish Foreign Minister Mevlut Cavusoglu. “We believe that it is in the interest of Turkey to follow up on the [ECHR] decisions.” For his part, Cavusoglu urged the EU to stop defending his government’s opponents and on Friday said Mogherini was “out of line.”