The Japanese ambassador is warning the federal government that delays in a major LNG plant near Prince Rupert could cost Canada a rare opportunity.

Ambassador Kenjiro Monji sent a letter to the Canadian Environmental Assessment Agency after the federal government announced Monday it would delay a final decision on the Pacific NorthWest LNG Ltd. project by three months. 

Japan is part of the proposal to build the $36-billion facility near Prince Rupert, partly as a potential market for liquefied natural gas. Monji said in his letter Canada could wait another decade before it finds the same access to Asian buyers, unless it acts quickly to develop and export the product. 

Environmental regulators have requested more details from the project consortium on the environmental impact of a 24-hour construction schedule. Specifically, regulators are worried about impacts to fish, marine mammals and human health. 

The proposed facility is backed largely by Malaysia's Petronas, which would build the natural gas liquefaction and export facility on Lelu Island.