Spanish Prime Minister Pedro Sanchez has rejected raising military spending to 5 percent of GDP as requested by NATO, describing the proposal as "incompatible," "unreasonable" and "counterproductive."

In his letter sent on Thursday to NATO Secretary General Mark Rutte, Sanchez pointed out that "committing to a 5 percent target would not only be unreasonable, but counterproductive," referring to the draft declaration presented by Rutte to the upcoming NATO summit in The Hague on June 24-25

He argued that each government can legitimately decide whether it is willing to make that sacrifice "as a sovereign ally, we choose not to."

Sanchez defended that what Spain is conveying is that his country "will need an expenditure of 2.1 percent according to estimates by our Armed Forces, an investment sufficient to acquire and maintain all the personnel, equipment, and infrastructure required by the alliance."

Sanchez offered Rutte an alternative to avoid "limiting the spending ambitions of other allies." The prime minister proposed "a more flexible formula" in the declaration, making "the spending target optional or excluding Spain from the application" of that 5 percent goal.