The U.S. held off on military strikes against Iran for a second consecutive day Sunday, while Tehran also said it had refrained from launching attacks, as diplomatic efforts continued to revive negotiations over an interim ceasefire that had been derailed by nearly two weeks of hostilities.

The specific reason for the U.S. operational pause was not immediately clear, the Associated Press reported.

American forces had recently carried out strikes on Iranian coastal targets and infrastructure following a sharp escalation that began after Iran fired on vessels transiting the Strait of Hormuz, a vital global shipping route. 

The Pentagon did not immediately comment on the pause, which is reportedly taking place after 13 consecutive nights of airstrikes.