Germany today slammed Turkey's refusal to allow its lawmakers to visit a NATO base near Syria and warned it could move its troops elsewhere.
Berlin described as "unacceptable" Ankara's latest ban on a visit to the Incirlik base in southern Turkey, used by international coalition fighting the Islamic State group.
Germany has more than 200 troops stationed there, flying Tornado surveillance missions over Syria and refuelling flights for partner nations battling IS jihadists.
Germany will now "look into alternative locations" for its military personnel, said Chancellor Angela Merkel's top spokesman Steffen Seibert.
Jordan offered "the best conditions", a defence ministry spokesman added, saying it had also looked at Kuwait and Cyprus since Turkey first denied such visits to German MPs for several months last year.
The defence ministry spokesman cautioned however that any move would involve shifting hundreds of containers of materiel and would take several months.
Turkey rejected the latest lawmakers' visit because of anger over Germany granting political asylum to some of its military officials since last year's failed coup against President Recep Tayyip Erdogan, foreign ministry spokesman Martin Schaefer suggested.
He said Ankara's reason may be "individual decisions of independent German authorities in connection with military members".
German media have reported that over 400 Turkish military personnel, diplomats, judges and other officials and their relatives had sought political asylum in Germany.
They fear being caught up in Turkey's crackdown against those Erdogan blames for the coup -- supporters of Fethullah Gulen, a reclusive US-based Islamic preacher who has denied the charges against him.
The vast crackdown has heightened tensions between Turkey and Germany, which is home to a three-million-strong ethnic Turkish population, the legacy of a massive "guest worker" programme in the 1960s and 1970s.
Both countries have sparred over a range of issues, including civil rights in Turkey, press freedom and the military campaign against Turkey's Kurdish minority.
Relations were strained further during the referendum campaign in April to boost Erdogan's powers, and since the arrest of Turkish-German journalist Deniz Yucel on terror- related charges in February this year.
Another row last year, centred on a sensitive historical question, had led Turkey to deny German lawmakers the right to visit Incirlik for several months.
The German parliament had voted in June to recognise the Ottoman Empire's World War I-era massacre of Armenians as a genocide.
After the vote, a furious Erdogan accused German lawmakers of Turkish origin of having "tainted blood".
Armenians say up to 1.5 million people were killed between 1915 and 1917 as the Ottoman Empire was falling apart.
Turkey rejects the claims, arguing that 300,000 to 500,000 Armenians and as many Turks died in civil strife when Armenians rose up against their Ottoman rulers and sided with invading Russian troops.
That row was only resolved after Merkel made clear the Armenia resolution was a political statement and not legally binding.