His Majesty Sultan Haji Hassanal Bolkiah Mu’izzaddin Waddaulah ibni Al-Marhum Sultan Haji Omar ‘Ali Saifuddien Sa’adul Khairi Waddien, Sultan and Yang Di-Pertuan of Brunei Darussalam yesterday sent congratulatory messages to Vietnamese President Nguyen Xuan Phuc, Prime Minister Pham Minh Chinh, the government and people of Vietnam on the occasion of its 77th National Day.