FRANKFURT (Reuters) - Tensions between Germany and Turkey are holding up planned defense projects at Rheinmetall, the German company’s chief executive told news agency DPA in an interview.

Ties between the two NATO allies have been strained by Turkish President Tayyip Erdogan’s crackdown on opponents after a failed coup last year as well as Germany’s refusal to extradite people Turkey says were involved in the plot.

Rheinmetall CEO Armin Papperger said in the interview published on Monday that several projects, including the production of ammunition for fighter jets in Turkey and upgrades to Turkey’s Leopard tanks, were still awaiting decisions by the two governments.

“If relations with Turkey don’t improve it will be difficult to obtain clearance from Germany,” he said.

Poor relations have also dimmed Rheinmetall’s prospects for playing a role in Turkey’s Altay tank project, worth an estimated 7 billion euros ($8.13 billion), DPA said.

Turkey’s BMC, with which Rheinmetall has a joint venture in Turkey, is among the bidders for the first tranche to build around 100 to 200 of a planned 1,000 combat tanks, DPA said.

If BMC wins the contract, Rheinmetall could in theory take part in the development of the tank via joint venture RBSS, in which the German company holds a 40 percent stake, but it would need an export clearance from the German government.

Papperger said Rheinmetall had no plans to build its own tank factory in Turkey.