German Foreign Minister Frank-Walter Steinmeier, left, and Turkish Foreign Minister Mevlut Cavusoglu speak before their meeting in Ankara, Turkey, Tuesday, Nov. 15, 2016. Steinmeier visits Ankara to discuss strained ties with Turkish leaders. (AP Photo/Burhan Ozbilici)

ANKARA, Turkey - German Foreign Minister Frank-Walter Steinmeier on Tuesday expressed "serious concerns" over Turkey's crackdown on opponents but said he favours continuing Turkey's European Union membership bid.

Steinmeier was speaking in Ankara a day after EU foreign ministers struggled to forge a common stance on Turkey amid deepening concerns about rights abuses, and Turkish President Recep Tayyip Erdogan suggested calling a referendum next year on whether his country should join the bloc.

During a joint news conference with his Turkish counterpart Mevlut Cavusoglu, Steinmeier said some within the EU wanted to break off Turkey's EU membership talks."

"Whether Turkey grows closer or distances itself from the EU is not a decision that can be taken in any European capital. It is a decision that needs to be taken by Turkey," Steinmeier said. "I personally favour a good and close co-operation based on trust ... I wish these relations to continue."

Cavusoglu said the Turkish nation was frustrated by what he said was the EU's "hypocrisy and double standards" toward Turkey and that was why the government was considering holding a referendum.

"Every day, one EU foreign minister comes up and says: 'let's throw Turkey out, let's throw them out of the negotiations, let's throw them out of NATO,'" Cavusoglu said.

"We don't deserve this treatment. Therefore let's ask our people and let the people decide. We are truly fed up with this approach that humiliates Turkey," Cavusoglu said.

Ties between Turkey and Germany have become increasingly strained. Erdogan has accused Germany of supporting terrorism after German authorities suggested that Berlin may not extradite suspects wanted by Turkey over the failed coup attempt in July, if it considers the cases are politically motivated. Erdogan has also accused Berlin of failing to clamp down on Kurdish militants allegedly operating in Germany.

Steinmeier said his country failed to understand claims by Erdogan that Germany had become "a safe haven" for terrorists and said Berlin stood with Turkey in its fight against the Islamic State group and the outlawed Kurdistan Workers' Party, or PKK.

On Monday in Brussels, EU foreign ministers struggled to find a common position that would balance their need for Ankara's continued support to stop a wave of migrants heading to Europe with concerns about rights abuses in Turkey in the wake of the quashed military coup in July.

Last week, 10 legislators from Turkey's pro-Kurdish party and several senior staff of the opposition Cumhuriyet newspaper were arrested on terrorism-related charges.

Turkey has arrested tens of thousands of people in its investigation into the failed coup, and dismissed or suspended more than 100,000 people from government jobs for their links to U.S.-based cleric Fethullah Gulen, who is accused of masterminding the attempt.

News from © The Associated Press, 2016