"Our colleagues have examined the details of the (S-300) deal over the past year, and it was decided that the system be supplied to Iran by the end of 2015," Dehqan told reporters before leaving Tehran for Moscow.
"The Russian side pursued the issue seriously and was willing to resolve it," the Iranian minister said, adding that he will sign the delivery deal during the visit.
His remarks came after Russian President Vladimir Putin decided on Monday to lift the ban on the S-300 missile system delivery to Iran.
The ban had been introduced by former Russian president Dmitry Medvedev in 2010.
Dehqan is making the trip at the invitation of his Russian counterpart Sergei Shoigu to attend and address the Moscow Conference on International Security (MCIS).
On the sidelines of the upcoming conference, Dehqan will meet with some of his counterparts from other countries for talks on bilateral, regional and international issues.
A press conference is also on the agenda of the Iranian minister during his visit to Moscow.
The conference, slated for April 16-17, will bring representatives of about 80 defense ministries together, Russian Deputy Defense Minister Anatoly Antonov has said.
"The Fourth Moscow Conference on International Security, an event annually organized by the Russian Defense Ministry, will take place on April 16-17. Defense ministers and delegations of defense agencies from 79 states, heads of international organizations, Russian officials, experts and academicians have been invited to the forum," Antonov was quoted as saying by Interfax.