Burma, officially the Union of Myanmar, is the largest country by geographical area in mainland Southeast Asia, or Indochina. The country is bordered by the People's Republic of China on the northeast, Laos on the east, Thailand on the southeast, Bangladesh on the west, India on the northwest, the Bay of Bengal to the southwest with the Andaman Sea defining its southern periphery. One-third of Burma's total perimeter, 1,930 kilometres (1,199 mi), forms an uninterrupted coastline.