"At the meeting of heads of state on July 4, the full membership of Iran will be approved," Lavrov said at the opening of an SCO centre in Moscow.
The SCO, which has its headquarters in China, is a diplomatic organisation with eight members, including India and Pakistan.
SCO membership was already on the cards and Iran is also hoping to be quickly accepted into another grouping that excludes Western countries – the BRICS group with Brazil, Russia, India, China and South Africa.
Belarus is also applying to join, and Lavrov said on Friday that next week's virtual summit would "begin the procedure" for that membership to go ahead.