The leaders of Japan and the Philippines agreed Thursday to sharply boost their defense ties, allowing Japanese troops greater access to Philippine territory, as tensions rise in Asia amid China’s growing influence.

Philippine President Ferdinand Marcos Jr. is visiting Japan shortly after he and U.S. Secretary of Defense Lloyd Austin reached an agreement on allowing the United States more access to Philippine military bases to keep China’s territorial ambitions in check.

The defense arrangement signed by Marcos and Japanese Prime Minister Fumio Kishida will allow Japanese troops to join training exercises to respond to natural disasters and humanitarian needs in the Philippines. The agreement is seen as a step toward broader military cooperation and could lead to similar agreements between Japan and other Southeast Asian nations.

Kishida said the two countries will continue talks to further strengthen and streamline their militaries' joint exercises and other operations, while seeking to expand the transfer of Japanese defense equipment and technology to the Philippines and strengthen cooperation trilaterally with the United States.

“After our meeting, I can confidently say that our strategic partnership is stronger than ever as we navigate together the rough waters buffeting our region,” Marcos said at a joint news conference with Kishida. "The future of our relationship remains full of promise as we continue to deepen and expand our engagements across a wide range of mutually beneficial cooperation.”

The new defense agreement allows Japan to deploy its forces for humanitarian missions and disaster response in the Philippines, an arrangement Japan hopes to eventually upgrade to include joint military training, cooperation and mutual visits, Japanese officials said.

The two leaders “resolved” to increase the defense capabilities of their own countries and strengthen overall security cooperation with reciprocal port calls and aircraft visits and the transfer of more defense equipment and technology, according to a joint statement released later Thursday. It said Japan will transfer air surveillance radar systems to the Philippines and provide related personnel training.

They “expressed serious concerns about the situation in the East and China Seas and strongly opposed the actions including force or coercion that may increase tensions," the statement said.

Kishida and Marcos also agreed to strengthen cyber and economic security. They also confirmed Japan’s continuing assistance to the Philippine coast guard in reinforcing its capabilities, including the improvement of port facilities at Subic Bay, a former U.S. naval base.

Last year, the two island nations held their first four-way security talks among their defense and foreign ministers and agreed to strengthen their defense ties.

Kishida’s government in December adopted key security and defense upgrades, including a counterstrike capability that breaks from Japan’s post-World War II principle of self-defense only, while also doubling defense spending in five years.

Under the new strategy, Japan will also use development assistance to support poorer nations as they strengthen their maritime safety and other security capabilities. It’s meant to counter China’s growing regional influence.

“President Marcos’s visit here gives us impetus for Japan and the Philippines to further elevate our cooperation in recent years to even higher levels as we contribute to the peace and stability of the region and the international community,” Kishida said at the news conference.

Kishida announced 600 billion yen ($4.6 billion) in economic assistance from the public and private sector for the Philippines through March 2024, primarily to improve infrastructure, such as construction of a commuter railway, and disaster response. The two sides also signed an agreement to work together in information and communication technology and to cooperate in energy security and industrial development.

“When you think about the stability in the region and sea lanes and deterrence of China’s maritime assertiveness, deepening cooperation with the Philippines is crucial for the security of Japan and the United States,” said Heigo Sato, a Takushoku University professor and expert on defense and security. “Having access to bases in the Philippines would expand strategic options for the Japan-U.S. alliance” in case of an emergency involving Taiwan and China, he said.

Japan has been expanding its military cooperation in recent years beyond its main ally, the United States, forging close ties with Australia and other countries in the Asia-Pacific region and Europe.

Marcos met with Emperor Naruhito and Empress Masako ahead of his talks with Kishida and invited the imperial couple to visit the Philippines. He said he plans to join talks with trade and business officials from the two sides before returning home on Sunday.