When U.S. President Donald Trump sat down to lunch with his Japanese counterpart this month, talk turned quickly to how Tokyo could help realize a decades-old proposal to unlock gas in Alaska and ship it to U.S. allies in Asia.

Trump and his energy tsar Doug Burgum framed the venture as a way for Japan to replace Middle East energy shipments and address its trade imbalance with the U.S., according to two officials briefed on the closed-door talks.

Prime Minister Shigeru Ishiba — eager to ensure a positive first meeting and stave off damaging U.S. tariffs — struck an optimistic note about the Alaska LNG project despite Tokyo's doubts about its viability.