TOKYO/WASHINGTON (Reuters) -The U.S. has invited officials from Japan, South Korea and Taiwan to Alaska to discuss projects including a vast gas pipeline, two people familiar with the planning said, as Asian governments consider U.S. investments in the hopes of relief from President Donald Trump's tariffs.

Trump's energy czar, Interior Secretary Doug Burgum, and Energy Secretary Chris Wright will host the June 2 event, the sources told Reuters, requesting anonymity as the details are not public.

The event will include a visit to Alaska's remote North Slope, one source said, home to stranded gas fields the U.S. is seeking to unlock through the proposed $44 billion pipeline. It would traverse 800 miles (1,300 km) across the huge state before the gas is liquefied for shipment, mainly to Asian customers.

Trump has pushed allies like Japan and South Korea to buy U.S. energy while threatening trade tariffs. He has said Tokyo and Seoul want to invest "trillions of dollars each" in the pipeline project.

It is unlikely the Alaska meeting will yield major deals related to the long-delayed pipeline project, as originally hoped, and the size and seniority of the foreign contingent is unclear, the sources said.

Japanese Prime Minister Shigeru Ishiba expressed optimism about the Alaska LNG project during a private meeting with Trump in February, despite doubts in Tokyo about its viability. Japanese and South Korean officials and executives have sounded caution on a project in the works for decades that has made little progress because of cost and logistical challenges.

The White House declined to answer specific questions about the event, saying in a statement that Trump "has a proven history of bolstering American energy production and will restore our nation's position as a global energy leader".

The Energy and Interior departments did not respond to requests for comment.

Officials from Taiwan's state-run energy company CPC, which in March signed a non-binding agreement to invest in and purchase offtake from the pipeline project, will attend the Alaska meetings, the Economic Ministry said. CPC did not respond to requests for comment.

South Korean Trade Minister Ahn Duk-geun said last week his government had been invited but that the timing was "very tricky". South Korea holds a presidential election on June 3.

Japan's trade minister, Yoji Muto, has also been invited, two sources said. A Japanese government source said it would be difficult for Muto to attend due to parliamentary commitments, while Tokyo's level of participation may be influenced by the progress of Japan-U.S. trade negotiations.

An official at Japan's trade ministry said on Friday that no decision had been made on Japanese participation.

Locking in binding agreements on the pipeline project may take time as developers have not yet conducted a front-end engineering design study, needed to clarify overall project costs, one source said. The study is expected to begin later this year.

The June 2 meeting will also broadly discuss collaborating on energy projects in the Arctic, the sources said. Burgum and Wright are then scheduled to participate in the Alaska Sustainable Energy Conference in Anchorage from June 3 to 5.