Ties and tensions between China and Japan

Here are some facts about relations between the two countries.

* China pulled ahead of Japan in 2010 to become the world's second-biggest economy behind the United States on a seasonally unadjusted, nominal dollar basis, with a GDP worth $5.88 trillion against Japan's $5.47 trillion. Japan and China together make up 18 percent of the world's economic output.

* China has been Japan's biggest trading partner since 2009. In 2010, trade between the two nations grew by 22.3 percent compared to levels in 2009, reaching 26.5 trillion yen ($327.8 billion), according to the Japan External Trade Organization.

Japan's shipments to mainland China accounted for 19.4 percent of its overall exports in 2010, making it the top destination for Japanese goods, followed by the United States at about 15.4 percent.

* China and Japan are the world's first and second-biggest holders of foreign reserves.

* China produces 97 percent of the world's rare earth metals, which Japan buys in large amounts for making electronics, magnets and clean technology.

* China set its 2010 rare earths export quotas 40 percent lower than 2009 levels, and has again cut quotas for the first half of 2011. Japan is worried about those cuts, especially after fears that China held back shipments of rare earths as punishment after the territorial dispute last year.

* Japan invaded and occupied part of China from 1931 to 1945. Bitterness over Japan's wartime atrocities still underpins widespread Chinese public distrust of Japan.

* China has criticised high-profile visits by Japanese leaders in the past to Tokyo's Yasukuni Shrine for the war dead. Among those honoured are war criminals convicted by an Allied tribunal after World War Two. Junichiro Koizumi, Japanese prime minister from 2001 to 2006, made annual visits to the shrine while in office, but his successors have stayed away.

* Public opinion in both countries reflects widespread mutual wariness, constraining the room policy-makers have to give ground. In 2005, occasionally violent protests against Japan broke out in several Chinese cities, reflecting anger over Koizumi's shrine visits and other tensions.

* A poll last year by Japan's Yomiuri news service and China's Xinhua news agency found 90 percent of Japanese surveyed said ties with China were bad and 87 percent said China could not be trusted. In China, 81 percent of respondents said ties with Japan were bad and 79 percent said it could not be trusted.

* Japan has been worried by China's military modernisation, with its double-digit defence spending rises and expanding naval reach. China has said its military budget will rise by 12.7 percent in 2011, reaching 601.1 billion yuan ($93 billion).

By contrast, Japan's massive public debt meant its defence budget for the year beginning in April was shaved 0.4 percent to 4.66 trillion yen ($57.6 billion), its ninth year of decline.

* The two nations have been at odds over China's exploration for natural gas in the East China Sea. In 2008, they agreed on principle to resolve the feud by jointly developing gas fields. Progress has been halting and Japan has accused China of drilling for gas in violation of the deal.

* The seas are at the centre of a territorial dispute between the two countries focused on a group of uninhabited islets, known as Senkaku in Japan and Diaoyu in China.

* In September 2010, Japan held a Chinese trawler captain after his boat collided with Japanese coast guard ships near the isles. Beijing cancelled diplomatic meetings in protest at Japan's detention of the Chinese trawler captain until he was released.

* That dispute subsided after Japanese Prime Minister Naoto Kan held an ice-breaking meeting with Chinese President Hu Jintao in November, but ill-will has lingered.

* The Chinese government offered support after a massive earthquake and subsequent tsunami devastated Japan on March 11. China voiced concern about radiation drifting from damaged Japanese nuclear power plants and restricted imports of some Japanese foods.

* In a gesture of goodwill in May, Chinese Premier Wen Jiabao and South Korea's President Lee Myung-bak met Japanese Prime Minister Naoto Kan in Fukushima city, about 60 km (37 miles) northwest of a stricken nuclear power plant that triggered the worst nuclear crisis since Chernobyl.

* Japan's Kan is considering visiting China in October, the Sankei daily said on Sunday.

Copyright Reuters, 2011