Russia's special envoy on Syria Alexander Lavrentiev is to arrive in Tehran today for discussions over the latest developments in the 6-year-old civil war in the Arab country. He will meet deputy foreign minister for Arab and African affairs, Hossein Jaberi Ansari and Secretary of Iran's Supreme National Security Council Ali Shamkhani, who is also Iran's high representative for the coordination of joint political, military and security activities with Syria and Russia, ISNA reported. Iran has been offering military advisory support to the government in Damascus after foreign-backed militants overran parts of Syria and unleashed a wave of terrorism in that country. Moscow has also been carrying out aerial bombardment campaign inside Syria against militants on behalf of Damascus. The three countries have coordinated a joint campaign against terrorism in Syria. Iran, Russia and Turkey, which together act as guarantor states for the Syrian ceasefire, have organized political talks between the conflicting Syrian groups in a peace process in the Kazakh capital Astana. The fifth round of Astana talks is scheduled to be held from June 12-13. Jaberi Ansari and Lavrentiev will lead the Iranian and Russian delegations in the meeting.