The attack, the third targeting military bases hosting foreign forces in a week, targeted the Besmaya base south of Baghdad on Monday night, read the statement, making no mention of casualties.
Spanish forces linked to the US-led coalition purportedly fighting Daesh (ISIL or ISIS), as well as NATO training forces, are present in Besmaya, according to Al Jazeera.
Earlier on Monday, US Secretary of State Mike Pompeo warned Iraq that the US would retaliate "as necessary" against any new assaults on Americans.
Since late October, there have been 24 rocket attacks on the US embassy in Baghdad or bases where foreign troops are deployed, killing three American military personnel, one British soldier and one Iraqi soldier.
Some 5,200 American troops are based in Iraq as part of the US-led coalition.