Chancellor Angela Merkel is mulling the withdrawal of all German troops from Turkey in a move that would further damage the deteriorating relationship between the two countries.
Merkel floated the idea after Ankara blocked a request from Germany's parliament to visit Incirlik airbase in southern Turkey where 250 German troops are stationed.
Germany uses the base as a launching pad for its part in the campaign against Isis, but Merkel announced on Monday (15 May) that troops may be moved elsewhere.
"We will continue to talk with Turkey, but in parallel we will have to explore other ways of fulfilling our mandate," she said.
"That means looking at alternatives to Incirlik, and one alternative among others is Jordan."
The move to block to German access to the airbase was in response to Berlin's decision to grant asylum to 414 Turkish military officers, diplomats and their families who sought sanctuary in Germany in the wake of the failed coup attempt last July.
Turkish President Recep Tayyip Erdoğan is believed to have arrested as many as 70,000 people in the post-coup crackdown, with those fleeing to Germany hoping to avoid arrest.
Germany is also protesting the arrest of two of its citizens, journalist Deniz Yucel and translator Mesale Tolu, on charges that claim they were assisting terrorists.
The row also escalated further during Turkey's referendum on constitutional reform in which Erdoğan was seeking additional powers. Erdoğan tried to host political rallies in Germany, where over a million Turks lived and were eligible to vote, but Merkel blocked the demonstrations, citing instability and security concerns.
In response, Erdoğan likened Merkel and the Germans to the Nazis, stating that blocking protests violated the principles Germany stood for.
Should the row escalate further, it threatens to create bigger problems for Europe as Erdoğan has threatened to scrap the EU migrant deal, which eases the number of refugees moving to the continent.
Erdoğan and Merkel are due to meet in Brussels for a Nato summit next week later in May.