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
Indonesia–Malaysia border dispute originated in 1969 when the two countries negotiated to delimit the common border of their continental shelf. As the two countries could not agree on the soveignty of the two islands, the continental shelf border was left off the 1969 agreement between the two countries. Indonesia claimed that the islands were theirs by virtue of the fact that they were located south of 4° 10" North which it said formed the maritime border between it and Malaysia by virtue of a straight line extension of the land border which ended on the east coast Sebatik island. Malaysia however, claimed