Tawi-Tawi (Tausug: Wilaya' sin Tawi-Tawi) is an island province in the Philippines located in the Bangsamoro Autonomous Region in Muslim Mindanao (BARMM). The capital of Tawi-Tawi is Bongao.It is the southernmost province of the country, sharing sea borders with the Malaysian state of Sabah and the Indonesian North Kalimantan province, both on the island of Borneo to the west.