TOKYO -- On his sixth visit to Japan in five years, Philippine President Benigno Aquino III on Wednesday criticized China's assertiveness in regional seas, a concern shared by both countries as they deepen their ties.

During his four-day visit, Aquino will hold talks with Japanese Prime Minister Shinzo Abe focusing on defence and security ties. They are expected to sign a deal confirming Japan's provision of 10 patrol vessels to the Philippine coast guard to bolster its patrolling capability around Manila-claimed South China Sea islands.

Since both countries are U.S. allies and share concerns over China's maritime activity, the Philippines is extremely important to Japan, said Kenko Sone, spokesman at Japan's Prime Minister's Office.

Asked about a U.S. role, Aquino said America's presence is crucial to the region's stability and that the international community should act proactively.

In a speech at a conference organized by the Nikkei business newspaper, Aquino criticized what he called China's "unlawful territorial claim" and hinted at similarities between Beijing's land-reclamation in the South China Sea and Nazi Germany's expansionist moves before World War II. He has drawn similar parallels in the past.

Foreign Ministry officials said Monday that Abe and Aquino were also expected to expand their defenceco-operation in other areas, including the transfer of Japanese military equipment and technology to the Philippines, possibly related to maritime reconnaissance. Tokyo eased a ban on military exports last year.

In a speech to the upper house of Japan's parliament, Aquino said that the maritime and coastal stability in the region is "at risk of being disrupted by attempts to redraw the geographic limits and entitlements outside those clearly bestowed by the law of nations."

He praised Tokyo's solidarity with the Philippines in advocating the problem and said "a country that we both have had difficulties with" was responsible for the problem, without mentioning China.

Under Abe's push to expand Japan's international defence role, Japan has been expanding its defenceco-operation with a number of countries to complement its cornerstone alliance with the U.S.

In Washington, the top U.S. diplomat for East Asia said Wednesday that China's behaviour in the South China Sea was posing a question about what kind of power China seeks to become.

"For China to assert its claims through large-scale land reclamation, through the deployment of paramilitary forces or military forces that its neighbours see as threatening, is inconsistent with the kind of region that you and I want to see," Assistant Secretary of State Daniel Russel told the Center for Strategic and International Studies think-tank .

In Tokyo, Japanese Defence Minister Gen Nakatani said he held talks with his Australian counterpart, Kevin Andrews, and they shared concerns. "We both strongly oppose the attempt to change the status quo by force, as we share grave concern about China's reclamation work," Nakatani told reporters.

Manila has protested over China's stepped-up reclamation work on Philippine-claimed islands and its manoeuvrs against Filipino air patrols and fishermen.

Associated Press writers Teresa Cerojano in Manila, Philippines, and Matthew Pennington in Washington contributed to this report.