Iranian Foreign Minister Javad Zarif said his nation “concluded proportionate measures in self-defense” after it attacked a military base where U.S. troops are stationed in western Iraq.

“Iran took & concluded proportionate measures in self-defense under Article 51 of UN Charter targeting base from which cowardly armed attack against our citizens & senior officials were launched,” tweeted Zarif. “We do not seek escalation or war, but will defend ourselves against any aggression.”