Visiting Vietnamese President Truong Tan Sang opened his country\'s embassy here on Saturday in order to cement bilateral ties. \"We are extremely happy to establish this symbol of our close relationship,\" Sri Lankan Prime Minister D. M. Jayaratne said at the opening ceremony. This is the first visit by a Vietnamese president to Sri Lanka in recent memory. Earlier in the three-day trip, the two sides signed an oil and gas exploration deal, a memorandum of understanding on cooperation in machinery manufacturing and some other agreements on finance, education, defence, politics and investment.