(Reuters) -- Some 250 German troops are stationed at Incirlik air force base, contributing to NATO's mission targeting ISIS militants in neighboring Syria. Turkish foreign ministry sources told Reuters a visit by German parliamentarians would not be appropriate at this time, without elaborating.

Turkey similarly refused access to German parliamentarians late last year, though that visit eventually went ahead.

"We will continue to talk with Turkey, but in parallel we will have to explore other ways of fulfilling our mandate," Merkel told reporters on Monday.

"That means looking at alternatives to Incirlik, and one alternative among others is Jordan," she said.

A German military survey team will visit Jordan in coming days to look at potential bases there, government sources said. Jordan is the preferred site, although facilities in Cyprus and Kuwait are also possible, they said.

For historic reasons and to prevent abuse of power, the German army is controlled by the parliament, not the government, meaning that lawmakers have the right to inspect its activities, including outside the country.