In a message to the new emir of Kuwait on Wednesday, Rouhani offered condolences on the “heart-breaking” death of Sheikh Sabah Al-Ahmad Al-Jaber Al-Sabah.
The president also praised the late emir's prominent role in establishing balance and moderation in the region.
"I hereby condole you, the Kuwaiti government and nation on the demise of the late emir, who played a significant role in establishing regional balance and moderation," Rouhani said.
He also wished divine mercy and blessing for Sheikh Sabah and patience and reward for the survivors.
Kuwait’s Crown Prince Sheikh Nawaf Al-Ahmad Al-Jaber Al-Sabah has been named as the successor to the late emir who died at age 91 on Tuesday.