The unveiling ceremony confirmed the construction of the refinery, which is currently being constructed across the harbour from Port Moresby and will process about 32,000 barrels of oil per day when in production.

"This is a simple opening ceremony, yet it marks a massive investment, the first of its kind in this country," the Prime Minister said.

"The Overseas Private Investment Corporation-backed investment by InterOil shows confidence which is symbolic of the underlying strengths of Papua New Guinea."

OPIC is an agency of the US Government.

The Prime Minister also commended InterOil for a making a full commitment to construction in a pre-election environment when other investors might have taken a 'wait and see' approach.

At the ceremony, InterOil also confirmed the construction progress of a second causeway and jetty, which the company said would give the project added flexibility. In addition, the ceremony unveiled the new administration and management facilities being built on site by a local contractor.

Last month InterOil received its first instalment of $US31 million from an $US85 million loan agreement with OPIC for the completion of the refinery.