Nippon Oil confirmed that it was in talks with Idemitsu and other refineries in Asia for the supply of oil products and that the crude processing deal with its rival is to help cover the expected shortfall.

An Idemitsu spokesperson said that the refinery in Okinawa was a likely choice amongst the company's refineries for the processing deal due to its spare capacity.

While the deal is almost a certainty, the details have yet to be finalised. Idemitsu plans to permanently close the Okinawa refinery next spring.