Boeing Co. is working with the U.S. and Vietnamese governments to lift the Southeast Asian nation’s aviation safety rating and help enable its state-run carrier to operate flights to as far as Los Angeles, an executive said.

“Right now, they don’t have Category 1,” Dinesh Keskar, senior vice president of Boeing’s Asia Pacific and India sales, said in an interview at the Singapore Airshow on Wednesday, referring to the U.S. Federal Aviation Administration’s rating system. “So we are working with the Vietnamese government and the U.S. government to open that up.”

Under the Convention on International Civil Aviation, also known as the Chicago Convention, each country is responsible for the safety oversight of its own carriers, according to the FAA website. The agency assesses regulators of nations that have airlines operating to the U.S. to determine whether their oversight meets global standards. Vietnam has a Category 2 ranking, which means its safety processes fall short, and the FAA is reviewing it.

Vietnam Airlines Corp. was considering flights to Los Angeles by late 2019 or early 2020, Chief Executive Officer Duong Tri Thanh said in November. The carrier has signed a preliminary agreement with Boeing to buy its widebody 777-8 jets, but a final order would depend on the country getting the upgrade, Keskar said, adding any airline needs to be sure of routes before placing large aircraft orders.

“The investment is big and you should be able to fill that airplane,” Keskar said. “We feel optimistic that this year will get them the Category 1.”

Vietnam Air is expanding its fleet in a market that the International Air Transport Association estimates will be among the world’s top five in terms of growth in the next 20 years.