President Recep Tayyip Erdogan warned on Tuesday that Turkey would bring the curtain down on its over half-century bid to join the European Union if new accession chapters were not opened.

Erdogan’s threat to say “goodbye” to the EU came just minutes after he rejoined Turkey’s ruling party in the first major change to take effect following a controversial vote to boost his powers.

Relations between Ankara and Brussels have tumbled to unprecedented lows following a failed military coup against Erdogan in July.

The EU is troubled by the state of human rights in Turkey, particularly after widespread purges, while Ankara has lashed out at what it sees as a lack of solidarity from the bloc.

Erdogan last month won a referendum on sweeping constitutional changes to create a presidential system.

“There is no option other than opening chapters that you have not opened until now,” Erdogan said, referring to the individual policy areas that need to be concluded before Turkey joins the EU.

“If you open, then great. If you don’t open, then goodbye,” Erdogan said. “Turkey is not their (the EU’s) doorman.”

Sixteen chapters have been opened out of a total of 35 since accession talks began in October 2005, although Turkey’s bid to be a part of the bloc dates back to the 1960s.

“First you have to handle these chapters and fulfill your promises. Then we will sit at the able and talk. Otherwise, we have nothing left to discuss with you,” Erdogan said.

Some EU states — led by Austria — have suggested that membership talks should be frozen.

But EU foreign affairs chief Federica Mogherini said on Friday that negotiations had not been halted and German Foreign Minister Sigmar Gabriel also said that Berlin was “strictly against breaking off the accession talks.”

Turkish Foreign Minister Mevlut Cavusoglu, in an interview with A Haber TV, indicated that Erdogan would finally meet top EU officials when he travels to Brussels for the May 24-25 NATO summit.

“Later, there will be a big summit, a Turkey-EU summit. The timing will be clear after the talks on the NATO margins,” Cavusoglu added.

Erdogan, who Monday returned from a visit to India, will however first be visiting Russia, China and United States in an indication of Turkey’s priorities.