Brunei–Malaysia border which are defined by agreements, from west to east, are as follows: Brunei and Malaysia in an Exchange of Letters on 16 March 2009, agreed to affirm the five agreements. The two countries also agreed to use the watershed principle to determine the remaining undelimited portions of the border. Brunei's maritime boundary with Malaysia until the 100 fathom isobath was inherited from the Sarawak (Definition of Boundaries) Order in Council 1958 No 1518 and the North Borneo (Definition of Boundaries) Order in Council 1958 No 1517, both of which defined the boundary between Brunei on the one hand, and Sarawak
Borders of Malaysia and southeast of the Malaysian coastline. There is also a dispute involving the alleged incursion into Malaysian territorial waters by land reclamation works by Singapore at the western entrance to the Straits of Johor. Borders of Malaysia The borders of Malaysia include land and maritime borders with Brunei, Indonesia and Thailand and shared maritime boundaries with China, Philippines, Singapore and Vietnam. Malaysia has a total land border length of 3,147.3 km. Malaysia's border with Brunei is 481.3 km in length. Except for its coastline with the South China Sea, Brunei is completely surrounded by Malaysia's state of Sarawak on the