The government of Papua New Guinea has pledged to look into the disappearance of 16 Indonesian nationals who entered the neighbouring country during 2014 and 2015, an official said.

Papua New Guinea will convey the results of its investigation to Indonesia through diplomatic channels, chief of the Indonesian delegation to a meeting of the Joint Sub-Committee on Security Matters (JSCSM), Commodore Atok Sutanto told ANTARA in Port Moresby.

The whereabouts of the 16 Indonesian citizens from Merauke district in Papua province are still unknown.

At the one-day meeting held on Wednesday, the Papua New Guinean delegation to the meeting also stated that Yakyu is part of the Indonesian territory and assured that incident like lowering Indonesias Red-and-White flag in the area will not recur.

"Papua New Guinea has pledged to prevent any recurrence of the incident in the future," said Susanto, who is also a high ranking officer for international relations at the National Defense Forces (TNI) Headquarters in Jakarta.

The 16 Indonesians entered Papua New Guinea via Torasi between 2014 and 2015. However, their whereabouts have been unknown since then.