Cambodian Prime Minister Hun Sen on Tuesday was optimistic about the country's steadily growing trade with Vietnam and foresaw that the bilateral trade volume would definitely reach 5 billion U.S. dollars by 2015. The two-way trade volume was valued at 3.5 billion U.S. dollars last year, up 25 percent year-on-year. Speaking at a meeting with visiting Vietnamese Deputy Prime Minister and Foreign Minister Pham Binh Minh, the premier highly spoke of good relations and cooperation between the two neighboring countries. He said the two countries needed to further develop interconnectivities such as roads, railroads, and air routes in order to support the greater development of economics, trade, investment and tourism. For his part, Pham Binh Minh pledged to encourage more Vietnamese investors to Cambodia in order to boost the bilateral trade volume to 5 billion U.S. dollars by 2015. Pham Binh Minh visited Cambodia at the invitation of Cambodian Deputy Prime Minister and Foreign Minister Hor Namhong. Earlier in the day, the two top diplomats co-chaired the 13th meeting of the Cambodia-Vietnam Joint Commission for Economic, Cultural, Scientific and Technical Cooperation. Both sides agreed to increase bilateral cooperation in economics, trade, investment, education, and tourism, according to Koy Kuong, spokesman for the Cambodian Ministry of Foreign Affairs. Vietnam is the fifth biggest investor in Cambodia, with 128 projects worth over 3 billion U.S. dollars by 2013, according to the Association of Vietnamese Investors in Cambodia. On tourism side, Vietnam ranked the largest source of tourists to Cambodia with 850,000 Vietnamese visiting the country last year.