Turkish President Recep Tayyip Erdogan on Tuesday warned the European Union that Ankara will walk away from its long-running membership process if new accession chapters were not opened.

"There is no option other than opening chapters that you have not opened until now. If you open, then great. If you don't open, then goodbye," Erdogan said after rejoining Turkey's ruling party in Ankara. "Turkey is not their (the EU's) doorman," he added.

"Chapter" is the name for policy areas which are being addressed in the long-running talks on Turkish membership of the EU.