The Iranian minister left Tehran for the Kazakh capital of Astana on Thursday to partake in the meeting.
General Ashtiani is going to deliver an address to the event and hold meetings with his counterparts on the sidelines of the conference.
The conference will reportedly review the regional security issues, including defense cooperation among the SCO states.
The SCO, a Eurasian political, economic, and security alliance, was formed in 2001 by Russia, China, Kyrgyzstan, Kazakhstan, Tajikistan, and Uzbekistan at a summit held in Shanghai.
Iran was accepted as a main member of the SCO by the vote of all member states at the conclusion of the 21st summit in Dushanbe in September 2021 and joined the organization officially and permanently during a virtual summit of the SCO hosted by India in July 2023.
The organization accounts for 40 percent of the world's population and 28 percent of the global gross domestic product (GDP).