The SCO was formed to oppose US interference in Central Asia by developing regional security cooperation between member states - China, Russia, Kazakhstan, Kyrgyzstan, Tajikistan and Uzbekistan.

Iran currently has observer status in the organization.

On Monday during his official visit to Tajikistan, Mottaki said Tehran has already applied to join the organization.

"Tajikistan has given us its support in the membership bid," said the Iranian minister after a meeting with Tajik President Emomali Rakhmon.