Iranian President embarks on official visit to Viet Nam President Mahmoud Admadinejad     HA NOI (VNS) — Iran's President Mahmoud Ahmadinejad will begin his official two-day visit to Viet Nam today.   The visit is being made at the invitation by President Truong Tan Sang, announced the Foreign Ministry yesterday. Since establishing diplomatic ties in 1973, Viet Nam and the Islamic Republic of Iran have seen progress in political and trade ties, with two-way trade turnover reaching US$165 million in 2011 and $61 million during the first half of this year. — VNS