The prime minister of the United Arab Emirates (UAE) started an official Vietnam visit Tuesday aimed at boosting trade and investment with the fast-growing Southeast Asian economy, officials said. Business delegations were due to meet in the capital Hanoi during the visit by Sheikh Mohammad bin Rashed al-Maktoum, who is also vice president of the oil-rich country and the ruler of Dubai. The premier was due to meet his Vietnamese counterpart Nguyen Tan Dung, and the two sides were due to sign legal pacts in investment, labour affairs and taxation, said the state-run Vietnam News Agency (VNA).