Japan has urged Papua New Guinea to improve internal security to allow the smooth implementation of the liquefied natural gas projects.
The Post Courier reports that Japan's Foreign Minister, Takeaki Matsumoto, put the request to his PNG counterpart Don Polye in Tokyo.
Mr Polye has been in Japan for the signing of the investment agreement for the protection and promotion of Japanese investments in PNG.
Japanese companies are participating in both the ExxonMobil-led project and the second LNG project operated by InterOil Corporation.
A number of disgruntled landowner groups have already disrupted the construction of the major gas pipeline being constructed for the first LNG project.
In recent months, killings and attacks have been reported in Southern Highlands, raising security concerns about the safety of developers and contractors.
The government has stationed police units in the oil and gas rich region.