A letter from the FAA warns Gov. Togiola Tulafono against implementing his executive order demanding Hawaiian's withdrawal in favor of another airline.

"To prevent or impede an air carrier's service at an airport is also inconsistent with the airport operator's contractual grant to provide reasonable and not unjustly discriminatory access to the airport," wrote Ronnie Simpson, the FAA's manager for the airports district office in Honolulu in the Wednesday letter.

The governor has complained that the Honolulu-based airline, which has a monopoly on the key route linking American Samoa to the U.S., overcharges and subjects local citizens to discrimination and ethnic harassment.

Airline spokesman Keoni Wagner said Hawaiian will continue to fly between American Samoa and Hawaii.

"Hawaiian is well acquainted with the laws and regulations under which it operates, and the FAA's letter is consistent with our view of the situation."

The governor, in a weekend radio address, insisted American Samoa controls its borders, and government approval is needed to clear any flights in or out of the territory.

But he was rebuffed by local lawyer Jeff Waller, who issued a legal opinion this week that while the governor would have the authority to set aside a foreign corporation's permit under American Samoan law, the U.S. Constitution requires the supremacy of federal law.

The opinion said the airline's authority to fly is granted by the FAA, not the territorial government.

It said federal laws and regulations are extensive and pre-empt "any state or territorial law concerning air carriers."

The opinion also notes that Tulafono had not alleged that Hawaiian presented false information to obtain its business license and, therefore, he did not appear to be trying to revoke its business license.

Even that, however, may not be able to stop the airline from operating under FAA authorization, he said.

Tulafono's office did not immediately reply to e-mailed questions.

Bill Mosley, spokesman in Washington for the Department of Transportation, which oversees the FAA, said neither Tulafono nor the airline had communicated with the department on the matter.

"If we receive a complaint from either side, then we will look into it," Mosley said.