Germany's military is unable to meet its medium-term readiness target should NATO call on its members to mobilize against an attack, officials said Monday.

The revelation follows days of embarrassing reports about equipment failures that included German army instructors being stranded in Bulgaria en route to Iraq when their plane broke down, and delays in sending weapons to arm Kurdish fighters because of another transport problem.

In the latest incident, the military said one of two aging C-160 aircraft flying German aid to Ebola-affected West Africa has also been grounded on the island of Gran Canaria since the weekend, awaiting repairs.

Asked about a Der Spiegel report that Germany at this juncture wouldn't be able to offer the appropriate number of military aircraft within 180 days of an attack on the NATO alliance, Defense Ministry spokesman Jens Flosdorff confirmed that was the case.

But, he said, Germany's short-term readiness isn't an issue.

"The alliance and defense capabilities aren't in question," he said.

Still, Flosdorff said a report written by outside experts due to be published next week wouldn't make for comfortable reading.

"We need to be prepared for the fact that we will be dealing with individual problems for some time, and I'm not talking about months but rather years," he said.

A retired top-ranking German general said the equipment failures show the country needs to spend more on defense.

Germany this year reduced defense spending by about 800 million euros to 32.44 billion euros ($41.30 billion) — far below NATO's recommended level of 2 percent of GDP.

"This is embarrassing for such a large country as Germany with such a big economy," former chief of staff Harald Kujat told rbb-Inforadio.

The equipment trouble has prompted widespread criticism in German media of Defense Minister Ursula von der Leyen and senior ministry staff.

Munich's Merkur newspaper joked grimly Monday that "the only threat that NATO poses to Russia right now is that (Russian President Vladimir) Putin might die laughing."