President Rodrigo Duterte toured on Sunday the largest Japanese warship, which has been on a four-day port visit to the Philippines.

The Japan Maritime Self-Defense Force (JMSDF) Escort Flotilla One comprised of helicopter carrier JS Izumo and guide-missile destroyer JS Sazanami arrived at Subic Bay in Olongapo City, Zambales province on Sunday and it will be there until June 8.

Accompanied by some government officials, such as Defense Secretary Delfin Lorenzana, Duterte was briefed by Rear Admiral Yoshihiro Goka, commander of the JMSDF Escort Flotilla One, during the tour.

In an interview after the tour, Duterte cited the "long historical friendship" of the Philippines and Japan.

He said Japan, through the Japan International Cooperation Agency, has been helping the country, particularly the troubled island of Mindanao.

"Our ties with Japan is historical and I know that we will be with them for all time. They can count on our gratitude for helping us and also our friendship to fight with them," he said.

"We have so many problems in this world and I said we are friends, historical ones. We have a lot to say thank you to you. And I’d like Japan to know that we are a people of gratitude," Duterte added.

Meanwhile, in a statement, the Philippine Navy said the Japanese ships' visit is expected to enhance the "already strong relations" between the two Navies.

The 25,000-ton JS Izumo is the largest warship of the JMSDF and has a complement of eight SH-60K patrol helicopters. Izumo and Sazanami have a combined compliment of 800 officers and crew members.

After their goodwill visit here, the ships will go to India to participate in the Malabar Naval Exercise. Celerina Monte/DMS