Moei River The Moei River forms the border between Thailand and Burma. The river is the scene of clashes between the Tatmadaw and Karen militias. Often Karen people cross the river either in order to enter Thailand as refugees or to go back to Burma. Moei River The Moei River (, , , ) is a tributary of the Salween River. Unlike most rivers in Thailand, the Moei River flows north in a northwest direction. It originates in Phop Phra District, Tak Province, flowing then from south to north across Mae Sot, Mae Ramat, and Tha Song Yang Districts, finally entering the
Malaysia–Thailand border and Siamese territories. This border ultimately became today's border between Malaysia and Thailand. Thailand regained control of the Kedah, Kelantan, and Terengganu during World War II when the Japanese handed them over to the kingdom, thus moving the Malay States-Siamese border southwards again. The states were returned to the British at the end of the war. There are two stretches of the Malaysia–Thailand border which is subject to dispute. The first involves the land border in the Bukit Jeli (Jeli Hill) at the headwaters of the Golok River and the second involves the continental shelf boundary in the Gulf of