China has ruled out a high-level meeting with Japanese leaders at the United Nations General Assembly in New York, as the dispute over Japan's detention of a Chinese trawler captain enters its third week.

China says it would be inappropriate to meet with Japanese leaders on the sidelines of the annual United Nations General Assembly  meeting this week in New York.

Foreign Ministry spokeswoman Jiang Yu blamed Japan for damaging bilateral relations by continuing to detain a Chinese fishing boat captain.

Jiang repeats Beijing's calls for the immediate release of the captain.  She dismissed arguments that Japan is following its judicial procedures and says Tokyo will suffer tougher measures for not releasing him..

Japanese officials detained the captain and his crew three weeks ago after his ship collided with two Japanese patrol boats.  The collision took place in Japanese waters near uninhabited islands that Tokyo and Beijing both claim.

Last week, Beijing suspended high-level exchanges and promised tough counter-measures after a Japanese court extended the captain's detention.  The crew and the boat have been freed.

Japan says the captain's case will be handled appropriately according to its laws.  Prosecutors have until September 29 to decide whether to bring charges.

Although China routinely rejects criticism of its legal proceedings as interference in its affairs, it repeatedly has called the boat captain's detention illegal.

Tokyo warned Beijing not to allow, what it describes as, extreme nationalism to be stirred up in both countries.

Emotions over the issue are high in China where anger over Japan's World War II occupation runs deep.  It has prompted small anti-Japan demonstrations in some Chinese cities.

Chinese nationalists are particularly sensitive about the disputed islands, which in China are called the Diaoyu, and in Japan are called the Senkaku.  Tokyo and Beijing are eager to secure access to the rich fishing grounds around the islands and the large mineral deposits believed to lie under the seabed.