Tokyo's Narita Airport has begun construction on a third runway to help cope with an explosion in foreign tourist arrivals.

The project, which kicked off on Sunday, will allow Narita to accommodate 500,000 landings and takeoffs annually by 2029, compared with 300,000 currently.

Narita, located about an hour's train ride from Tokyo, serves as one of the two major international gateways to Tokyo along with Haneda Airport.

The expansion, which will also include lengthening the second runway, will almost double the size of the airport.

Airport chief executive Akihiko Tamura said the project will help boost Japan's international competitiveness.

"It is an urgent issue to further enhance the functions of the airport to strengthen the international competitiveness of Japan and the Tokyo metropolitan area, to increase the number of foreign visitors to Japan, and to promote the development of the areas surrounding the airport," he said at an opening ceremony on Sunday.

The record number of tourists descending on Japan every month is infusing energy into the nation's fragile economy while also causing congestion at popular destinations like Kyoto.

The government has set an ambitious target of almost doubling tourists to 60 million annually by 2030.

For the first four months of the year, Japan welcomed 14.4 million visitors, a rise of 24.5 percent from a year ago. (AFP)