Governor David Ige said Thursday it’s a top priority for Hawaii that the U.S. be able to process Japanese travelers for immigration and customs before they even get on a plane for the islands.

Ige, speaking to tourism industry officials, said he heard during a recent visit to Japan that the number of Japanese travelers to Hawaii could jump 20 percent if tourists were able to clear U.S. immigration and customs while at Tokyo’s Narita International Airport.

Hawaii Tourism Authority data show 1.5 million travelers from Japan visited Hawaii last year, more than from any other foreign country.

The U.S. government’s pre-clearance program allows Customs and Border Protection officers stationed abroad to decide whether to admit passengers and their belongings before they leave a foreign port.

The U.S. Department of Homeland Security said in May it would begin talks to expand pre-clearance to 10 new foreign airports, including Narita. Canadian travelers already clear customs before they leave Canada, which Ige noted.

Ige said he told Japanese Prime Minister Shinzo Abe and U.S. officials how vital this program would be for the islands.

“I’ve been working with Japan and the United States, making it clear to both governments that there’s nothing more important to the state of Hawaii than pre-clearance form Narita International Airport,” Ige said to applause from hundreds of industry officials attending the Hawaii Tourism Conference.

Ige said he’s also working to speed up immigration and customs processing here in Hawaii and upgrade the state’s airports to improve the visitor experience.

The governor spoke a day after the Hawaii Tourism Authority released data showing more than 816,000 travelers visited Hawaii last month, an all-time high. Tourists spend $1.4 billion during their time in the islands. Tourism is Hawaii’s biggest industry, employing more than 200,000 people.