BERLIN: An ally of German Chancellor Angela Merkel on Friday urged the European Union to suspend accession talks with Turkey over a purge launched by the government against suspected plotters of last week's failed coup.

European officials have called on the Turkish government to respect the rule of law in a sweep against soldiers, police, judges, civil servants and teachers, who have been suspended, detained or investigated over Friday's attempted putsch.

"If one sees how Turkey is dismantling the rule of law ...then these (EU membership) negotiations must be stopped immediately," said Horst Seehofer, who heads the Bavaria-based sister party to Merkel's Christian Democrats (CDU).

"No democratic constitutional state acts like this," the leader of the Christian Social Union (CSU) party told the Funke Media Group in an interview.

Merkel told President Tayyip Erdogan during a phone call on Monday that Turkey cannot join the EU if it reinstates the death penalty, which has been advocated by members of his AK party.

Turkey abolished capital punishment in 2004, allowing it to open EU accession talks the following year, but the negotiations have made little progress.

The EU struck a deal in March to reward Turkey for preventing migrants from crossing to Greece by channeling aid to Syrian refugees in the country, reviving accession talks and scrapping visas for Turks wishing to visit Europe.

The deal has not been finalized.

A spokesman for Merkel told a news conference on Friday that Germany was monitoring developments in Turkey and that any decision on the course of accession talks would be a collective EU decision.