Foreign Minister Li Zhaoxing said China would not be the first to use nuclear weapons "at any time and under any condition," the official Xinhua news agency reported.

"China has consistently observed the commitment since its first nuclear test in 1964," Xinhua said late Thursday, quoting Li as saying such a stance "will not be changed in the future."

The rebuttal followed reported comments by a professor at China's National Defence University who said China could use nuclear weapons to retaliate against the United States if it attacked in any conflict over Taiwan.

"If the Americans draw their missiles and position-guided ammunition on to the target zone on China's territory, I think we will have to respond with nuclear weapons," General Zhu Chenghu was quoted as saying.

His comments were reported July 15 in the Financial Times and the Asian Wall Street Journal, which attended a briefing with the general organised by a private Hong Kong group, the Better Hong Kong Foundation.

"If the Americans are determined to interfere (then) we will be determined to respond," said Zhu.

Analysts said the remarks were largely rhetoric but also indicated that Beijing wanted to show the United States it was serious about Taiwan.

Li insisted the general was speaking in a personal capacity only.

"What the researcher said was only his personal view and did not represent the stance of the Chinese government," he said.

China had initially responded to the reports not by dismissing them but by insisting it would resolutely seek to resolve the Taiwan issue in a peaceful manner.

The United States said the general's remarks were "unfortunate" and it hoped they did not reflect the views of the Chinese government.

"With respect to the general, it will be interesting to see to what extent his remarks do or do not reflect the views of his government, and I prefer to wait and see what transpires there," US Defense Secretary Donald Rumsfeld said on Monday.

Li's rebuttal came in a week during which the United States released a report which said the size and pace of China's weapons acquisitions could threaten the military balance with Taiwan and pose a threat to others in Asia.

China strongly protested, calling in the deputy chief of mission at the US embassy in Beijing, and the White House took pains to emphasise that it did not view China as a threat.

China and Taiwan split in 1949 at the end of a civil war but Beijing still claims it as part its territory and has repeatedly threatened to invade if the island formalises its 56-year separation with a declaration of independence.

Despite hia conciliatory comments, Li also insisted that China "will never allow anyone or any force to separate Taiwan from China by any means".

In March China adopted a law allowing it to use force against any secession moves by Taiwan, triggering concerns in Washington and raising tensions in the region.

Since the United States switched diplomatic recognition from Taipei to Beijing in 1979, Washington has acknowledged Beijing's position that Taiwan should be considered an integral part of China.

Yet the United States remains the leading arms supplier to Taiwan because it is bound by law to offer the island the means of self-defence if its security were threatened.