The four companies agreed to "evaluate the commercial feasibility of utilizing North Slope natural gas delivered to Southcentral Alaska via the Alaska LNG Project to produce carbon-free ammonia," AGDC said.

Carbon dioxide (CO2) emissions from production of the hydrogen-rich fuel can be captured and stored underground in the Cook Inlet basin, which has "world-class carbon sequestration potential," Alaskan state-owned AGDC added.

Japan, the world's fifth-biggest CO2 emitter, is targeting growing its demand for fuel ammonia, which does not emit CO2 when burnt for energy, to 3 million tonnes a year by 2030 from zero now, reflecting its 2050 goal to become carbon neutral.

The costs and emissions associated with shipping ammonia to Asian markets from Alaska are lower compared to the U.S. Gulf Coast, AGDC said.

Japanese companies are also looking to invest in the Canadian province of Alberta to produce ammonia and methanol in the effort to build global supply chains of greener energy to fight climate change, a provincial minister said on Monday.

(Reporting by Deep Vakil in Bengaluru; Editing by Lisa Shumaker)