Sakhalin Energy, which operates a liquefied natural gas export plant in the Russian Far East, wants to raise long-term contract prices, threatening to push up energy costs in Japan and South Korea.

Discussions with customers in North Asia began late last year as part of a regular price review conducted every five years, according to people with knowledge of the matter. While Sakhalin Energy sees a tighter gas market now compared to when the previous review was held, the buyers haven’t yet accepted the proposal for higher rates, said the people, asking not to be named because the information was private.

Sakhalin Energy LLC didn’t immediately respond to a request for comment.

The move bucks a wider trend of falling prices in long-term LNG contracts. The market is expected to be oversupplied as soon as next year with the start of new projects in the US and Qatar, prompting suppliers to cut rates to lock-in customers.

The Sakhalin-2 LNG export plant is the closest to North Asia, home to the world’s top buyers. The facility supplied nearly 10% of Japan’s LNG needs last year, and hasn’t been targeted by Western sanctions due in part to the need to ensure energy security.

Sakhalin Energy is requesting long-term LNG prices in the range of a 14% link to Brent crude, according to the people. The value of the shipments is determined as a multiple of the oil price, a common practice for contracts of the super-chilled fuel.

Contract prices are currently in the 13% range, the people added.

More than half of Sakhalin-2’s exports went to Japan last year, according to ship-tracking data. Sakhalin Energy has supply contracts that last into the early-2030s with Japanese importers including Tokyo Gas Co. and Kyushu Electric Power Co., according to data compiled by BloombergNEF.