Tension between China and Taiwan began rising just over a week ago, when the Taiwanese President, Lee Teng-hui, called for relations between the two sides to be redefined as state-to-state ties.

Mr Jiang told Mr Clinton in a phone conversation that the Taiwanese leader had taken "a very dangerous step ... toward splitting the country," according to the Chinese news agency.

Taiwan was part of Chinese territory and Beijing would brook no separation, he said.

A Taiwanese foreign ministry spokesman responded to Jiang's comments by saying Taipei would not bow to pressure from Beijing to isolate it internationally, demanding "the reality of our existence be better understood by the world and that our voice be heard."

BBC Beijing correspondent James Miles says President Clinton's telephone call to his Chinese counterpart late on Sunday was a clear sign of Washington's concern over the escalation of tension between China and Taiwan in recent days.

Use of force

The Chinese president told Mr Clinton that Beijing would not "sit idly by and do nothing if foreign forces interfere in China's reunification cause".

The BBC's James Miles: "China building up the level of tension according to a familiar pattern"

"We are not committed to abandoning the use of force on the Taiwan issue because there are certain forces both within the island and in the world that attempt to separate Taiwan from the motherland," Mr Jiang is quoted as saying.

The army has openly vowed to take action if Taiwan moves towards seeking independence. The United States has repeatedly warned Beijing that it will not tolerate a violent solution to the Taiwan issue.

A White House spokesman said Mr Clinton expressed the hope that the issue would be resolved peacefully.

Military exercises

China says Mr Lee's comments are a violation of the "One China" principle

Last week, Beijing staged a 12-hour exercise involving more than 100 civilian vessels in the Taiwan straits - practising a rapid call-up in case of war.

Large-scale army, navy, and air force exercises are also being planned along the coast in Zhejiang province and the city of Shanghai, according to the independent Hong Kong daily Ming Pao.