Germany set up the 100 billion-euro special fund to purchase modern weapons and pledged to reach NATO's target of spending at least 2% of gross domestic product on defense, as part of a major policy shift in response to the Russia-Ukraine war, Reuters reported.
The missing sum, which Spiegel said came from an internal analysis of financing needs from the defense ministry, is based on the assumption that 2% of GDP in 2028 would be around 97 billion euros.
Ministry staff expect that an additional 10.8 billion euros would be needed on top of that to meet the troops' spending needs, Spiegel reported.
However, the regular defense budget was expected to remain at its current level, amounting to some 51.9 billion euros in 2028, the report said.
The defense ministry did not immediately respond to an emailed request for comment.
By comparison, the German government registered defense spending of 89 billion euros with NATO for this year, or 2.12% of GDP, according to Spiegel.