The Trump administration won’t approve a travel ban for Hawaii unless it receives input from Gov. David Ige first.

While three of Hawaii’s four county mayors have sent a letter to President Donald Trump asking that nonessential travel to the islands be suspended, Ige has so far been reluctant to sign on to such a proposal.

The governor said Friday that a mandatory 14-day quarantine for travelers in the islands is the best way to restrict visitor travel. A travel ban could come with too many complications, Ige warned.

“It would be difficult to implement, and impossible to enforce,” Ige said.

A White House spokesman said the president has received the letter and that he is looking forward to working with the governor and local officials to address the pandemic.

Ige had previously said during a Wednesday evening press briefing that he would consider signing on to the mayors’ letter to Trump. 

Later that evening, according to his spokeswoman Cindy McMillan, he decided against it. 

“His rationale was that he was concerned about the unintended consequences,” McMillan said.

Ige elaborated on those unintended consequences Friday. He said a travel ban poses a number of challenges. For one, Ige said an airline couldn’t discriminate against who decides to fly. Deciding what could be essential travel could also complicate matters, Ige said.

Ige said that he has been in contact with the Federal Aviation Administration and federal officials regarding a possible travel ban, but has decided it’s too hard to implement.

Only the federal government has the authority to halt air travel anywhere. The FAA can ground flights and restrict access to airspace, as they do when officials are investigating a crash site.

Honolulu Mayor Kirk Caldwell said at a press conference Thursday that the White House wanted Ige to weigh in first.

“We are hoping he will,” Caldwell said. “We are grateful for what he’s done. We just want to take it one more step.”

Caldwell’s office did not respond to a request Thursday for a copy of the mayor’s correspondence with the White House.

Only Hawaii County Mayor Harry Kim did not sign the mayors’ letter. Kim worries that a travel ban could hinder Hawaii’s economic recovery coming out of the pandemic, Hawaii Public Radio reported.

Kim also believes the mandatory quarantines are enough to halt travel.

Air travel has nearly stopped for the islands. But even with the quarantines, 89 visitors found their way to Hawaii Thursday, according to the Hawaii Tourism Authority. 

At last count, there were almost no international passengers, and domestic travel is down 99% compared to this time last year, according to the state Department of Business, Economic Development and Tourism.