The defense chiefs of Japan and the United States have agreed to strengthen the bilateral alliance under the administration of US President Donald Trump.

Japanese Defense Minister Nakatani Gen and US Secretary of Defense Pete Hegseth held their first telephone talks on Friday morning, Japan time.

Nakatani began with extending his condolences to the families of the victims of the fatal collision between a passenger plane and a military helicopter that occurred near Washington on Wednesday, local time.

The two leaders confirmed that Japan and the US will further strengthen the alliance's capabilities to deter and respond amid the worsening security environment in the Indo-Pacific. Russia and China have been increasing their military activities in the region.

The two agreed that Japan's Self-Defense Forces and the US military will continue the initiatives to reinforce the alliance through joint exercises and other activities.

The initiatives include the upgrading of the respective command and control framework and expansion of the bilateral presence in Japan's southwestern region including Okinawa Prefecture.

They also reaffirmed that Article Five of the Japan-US Security Treaty applies to the Senkaku Islands---obliging the US to defend the territories.

Japan controls the islands. The government maintains the islands are an inherent part of Japan's territory. China and Taiwan claim them.

The defense chiefs agreed that Nakatani will visit the US and the two will meet in person as soon as possible.

Nakatani stressed the need for close cooperation among Japan, the US and other like-minded countries to oppose any attempt to change the status quo by force. He also explained Japan's efforts to fundamentally strengthen its defense capability.

Speaking to reporters after the talks, Nakatani said that strengthening the Japan-US alliance is the most important policy of the administration of Prime Minister Ishiba Shigeru.

He added that he hopes the two countries will closely communicate with each other as trusted partners.