The appointment came Thursday in an official letter, in which the Leader thanked Jalili for his years of service as the leading member of the SNSC.
In a separate decree, Ayatollah Khamenei also appointed current SNSC Secretary Rear Admiral Ali Shamkhani as his representative to the top national security body for the next three years, citing the Constitutional Article 176.
In the decree, the Leader also thanked President Hassan Rouhani for his years of service as the Leader's representative at the SNSC.
The development came after Rouhani appointed former defense minister, Shamkhani, as the new SNSC secretary on Tuesday.
Shamkhani replaced Jalili, who represented Iran in the comprehensive talks with the P5+1 group of world powers, consisting of five permanent members of UN Security Council - Russia, China, Britain, France, and the US - plus Germany.
Shamkhani, a deputy commander of Iran’s Islamic Revolution Guards Corps (IRGC) during the 1980-88 Iraqi imposed war, went on to become commander of Iran Navy after the end of the war.
He served as defense minister in the two administrations of former president, Mohammad Khatami, from 1997 to 2005.
Shamkhani also serves as an adviser to Ayatollah Seyyed Ali Khamenei on military affairs.