Japan's prime minister urged China to act as a "responsible" member of the international community and raised concern over its expanding maritime activity in Asia, including in disputed waters where a ship collision ignited a bitter diplomatic feud.
Prime Minister Naoto Kan's comments Friday came after three Japanese held by China for allegedly entering a restricted military zone returned home — a sign that tension between the two Asian giants was easing somewhat.
Still, Kan took a serious tone in his first major policy speech to parliament since surviving a leadership challenge last month, stressing the need for Japan to adopt a more "active" diplomacy and defense policy that can deal with "uncertainty and instability that exist in areas surrounding our country."
He urged China, Japan's biggest trading partner, to act as a "responsible international community member," calling on both countries to deepen relations and promote economic cooperation to contribute to regional peace.
"The rise of China has been remarkable in recent years, but we are concerned about its strengthening defense capability without transparency and accelerating maritime activities spanning from the Indian Ocean to the East China Sea," he said.
In response, China called for Japan to keep up the relationship. "I hope Japan will work with China to jointly maintain relations between the two countries," Foreign Ministry spokesman Ma Zhaoxu said Friday in a brief statement posted on the ministry's website.
Meanwhile, China's national tourism office warned its citizens to be careful when visiting Japan, saying in a statement on its website that Chinese tourists in Fukuoka on Wednesday had been harassed by "Japanese right-wingers."
Relations plunged to their lowest level in years in recent weeks following the arrest of a Chinese fishing boat captain after his vessel collided with Japanese patrol boats near a string of islands in the East China Sea claimed by both countries.
The incident stirred up nationalism in both countries. Beijing suspended ministerial-level talks with Tokyo and postponed talks on jointly developing undersea gas fields. Japan released the captain last weekend, but Beijing shocked Tokyo by demanding an apology — prompting Kan to counter that China needed to cover damage to the patrol boats.
But a thaw began earlier this week with Beijing lifting a de facto ban on rare earth materials needed for advanced manufacturing and Thursday's release of three of four Japanese detained for questioning after allegedly entering a restricted military zone. The three men, employees of Japanese construction company Fujita Corp., arrived back in Tokyo Friday afternoon.
Tokyo is pressing China to release the fourth man who remained under house arrest and was being investigated for illegally videotaping military targets. The four were in China working to prepare a bid for a project to dispose of chemical weapons abandoned by the Japanese military at the end of World War II, according to Fujita.
Tokyo had said China needs to resolve the case of the four as the first step toward repairing ties. China's Foreign Ministry has denied any link between the detentions and the collision.
Despite the recent moves, relations between the two nations — the world's No. 2 and No. 3 economies — remain strained, and there were no plans yet for Kan to meet his counterpart, Wen Jiabao, at an Asia-Europe summit in Brussels early next week.
"I expect China's appropriate role and actions as a responsible member of the international community," Kan said in his speech. "If problems occur between Japan and China, it is important for us neighbors to respond calmly," a veiled criticism of Beijing's strident demands surrounding the ship incident.
Kan reiterated Tokyo's territorial claims over the uninhabited islands, called Senkaku in Japanese and Diaoyu in Chinese. He said Japan merely handled the collision under domestic law as "territorial disputes do not exist" in the area.
He also said Japan will issue a revised defense policy by December to develop "a truly useful and effective defense capability adequate to the coming era."
Japanese officials have raised concerns over the surging number of Chinese commercial ships venturing from shore, while China's navy and marine enforcement vessels are enforcing claims in disputed waters near the Senkaku islets and elsewhere that China is in dispute with other Asian countries.
Last week, President Barack Obama and leaders from Southeast Asia sent China a firm message over territorial disputes in the South China Sea, calling for freedom of navigation and peaceful resolution of disputes. Beijing regards U.S. involvement in the matter as unwelcome outside interference.
In August, a Chinese survey ship allegedly entered Japan's disputed exclusive economic zone without prior notification, breaking a previous agreement between the two countries. And in April, a Chinese helicopter came within 300 feet (90 meters) of a Japanese military monitoring vessel in the vicinity of a Chinese naval exercise.
The latest incident occurred during a seasonal surge of Chinese fishing boats in the disputed area in recent weeks. Since mid-August, the coast guard spotted as many as 270 Chinese fishing boats near the disputed islands per day, with 70 of them entering Japanese waters, according to the Coast Guard.
Foreign Minister Seiji Maehara struck a conciliatory tone Friday in comments at a news conference in Tokyo.
"Japan and China need to seek ways to prevent a recurrence of similar problems and reach a firm agreement," he said. "We are always open to dialogue. Our door is always open."
Associated Press writers Malcolm Foster and Shino Yuasa in Tokyo contributed to this report.