Beijing urged Washington Tuesday to stop selling weapons to Taiwan, saying the Chinese Government and people "have always been firmly opposed" to such sales.

The United States would violate commitments made in the three Sino-US joint communiques, in particular the joint communique signed between the two countries on August 17, 1982, if it offered arms to Taiwan, Foreign Ministry spokesman Liu Jianchao said yesterday at a regular news briefing in Beijing.

The sales undermine China's national security and the country's great cause of peaceful reunification, Liu said.

"We urge the US to abide by the one-China policy that has been repeatedly reiterated by President George W. Bush and the US Government, and honour its commitment to conform to the three joint communiqus signed by the two countries and oppose Taiwan independence," Liu said.

"The US should stop weapons sales to and military links with Taiwan, and send no wrong signals to Taiwan-independence forces."

The strongly worded warning against arms sales came after Stephen Young, director of the American Institute in Taiwan (AIT), urged Taiwan over the weekend to sign on to a multi-billion-dollar US weapons package intended to bolster the island's defences.

"The United States is watching closely and will judge those who take a responsible position as well as those who play politics on this critical issue," Young said.

Taiwanese "legislators" described the US official's remarks as an "ultimatum" to Taipei.

Liu said the Chinese Government had made solemn representations to Washington over the remarks by Young.

The arms bill called for the purchase of a US$16 billion package of Patriot missiles, submarines, and submarine-hunting aircraft.

The 5-year-old offer, made by Bush shortly after taking office, was one of the biggest proposed arms sales to Taiwan. However, the arms package has been repeatedly blocked by Taiwan's opposition and independent "lawmakers."

At the news briefing, Liu also urged all parties concerned with Iran's nuclear issue to refrain from taking any action that may lead to an escalation of the situation.

He said some new situations had emerged in the issue, and China will continue to consult with other members of the United Nations Security Council on relevant issues.

Iran confirmed it had launched a second cascade of centrifuges last Sunday and vowed to press ahead with the peaceful use of nuclear energy.