TOKYO - Japan's new prime minister will seek to keep periodically fraught ties with China and South Korea on track at weekend summits, avoiding rows that could hurt economic links and pitching his idea of an East Asia regional grouping.

A meeting of leaders from China, Japan and South Korea in Beijing on Saturday is also likely to discuss what could come next for the regional partners after North Korea signaled this week it could return to nuclear disarmament talks.

Prime Minister Yukio Hatoyama is expected to be conciliatory with China despite rivalry and worries about Beijing's military build-up, but analysts say it will take time to build trust given China's bitter memories of Japan's wartime occupation.

Given growing economic ties, there is no worry about a drastic worsening of the Japan-China relationship, Hu Wei, professor and dean of School of International and Public Affairs at Shanghai Jiao Tong University, told reporters in Tokyo.

But there is still a gap between their values and public sentiment, so you cannot be fully optimistic.

Japan's ties with China chilled markedly during then-prime minister Junichiro Koizumi's 2001-2006 tenure. His visits to Tokyo's Yasukuni shrine for war dead outraged Beijing, which sees the Shinto shrine as a symbol of Japan's past militarism.

But the need to thaw Sino-Japanese relations, given deepening economic ties, prompted all three of Koizumi's Liberal Democratic Party successors to refrain from paying respects at the shrine.

Hatoyama, whose Democratic Party ousted the long-dominant LDP in an August 30 poll, has also said he will not visit Yasukuni.

Getting along is essential for both Tokyo and Beijing.

China is now Japan's biggest trading partner and the second largest export destination after the United States.

But Tokyo faces the tough challenge of responding to Beijing's rising global clout. Some analysts expect China to surpass Japan as the world's No.2 economy late this year or next.

Leaders in both Japan and China know it would not be wise to quarrel, University of Tokyo professor Akio Takahara said. Healthy competition is good, but they know it should not be a zero-sum game.

REGIONAL COOPERATION

Hatoyama says he wants deeper ties with Asia and to steer a diplomatic course more independent of the United States.

Climate change and the fate of North Korea will be high on the agenda at the summit. But Japanese officials say Hatoyama will focus on building personal ties with his counterparts rather than getting down to the nitty-gritty of policy challenges.

Hatoyama, Chinese Premier Wen Jiabao and South Korean President Lee Myung-bak will issue two joint statements after the summit -- one on balancing economic growth and preserving the environment and the other on deepening win-win political and economic ties among the three countries, they added.
Hatoyama and Lee, who will hold a separate bilateral summit on Friday in Seoul, are likely to be keen to hear directly from Wen on Beijing's take on North Korea's nuclear arms ambitions after his rare visit to Pyongyang this week.

Japan also wants to firm up the idea of forming an East Asian Community inspired by the European Union.

The idea has been floated since the 1990s, when it ran into U.S. opposition, and is now the focus of annual regional summits. Tokyo has acknowledged that it would take decades to boost political integration and create a common currency in a politically and culturally diverse region.

This would be a worthy objective, but realizing it would be a very distant goal, said Liu Jiangyong, professor at Tsinghua University in Beijing.

(Additional reporting by Chris Buckley, editing by Ron Popeski)