Chinese President Hu Jintao denounced the Taiwanese president's decision to scrap an agency dedicated to uniting Taiwan with the communist mainland, and warned Tuesday that Beijing will not permit the self-ruled island to pursue formal independence.

Hu's criticism came amid a series of stern Chinese statements Tuesday that vilified Taiwanese President Chen Shui-bian but refrained from repeating Beijing's frequent threats to attack the island, which it claims as part of its territory.

The Chinese Foreign Ministry called on the United States, Taiwan's only major ally, to block any moves toward independence for the island, split from the mainland since 1949.

Hu accused Chen of taking a "dangerous step" toward independence.

"We will continue to strive for the prospect of peaceful unification, but we will never allow Taiwan to be split from the motherland," state media quoted Hu as saying.

The high-level warning reflected the depth of Beijing's alarm at Chen's decision Monday to abolish the National Unification Council along with guidelines calling for uniting Taiwan with the communist mainland.

Chen "is determined to push 'Taiwan independence' to create antagonism and conflict within Taiwan and across the strait," the ruling Communist Party said in a statement carried by the official Xinhua News Agency.

"It will only bring disaster to Taiwan society," the statement said.

In Washington, State Department spokesman Adam Ereli, speaking before China reacted to Chen's decision, appealed for calm and urged both sides to resume stalled talks on closer relations. Ereli called on Chen not to take any unilateral steps to change Taiwan's status.

"We will continue to hold President Chen by his commitments not to take unilateral moves," Ereli said. "We will be following events closely."

Japan urged Taiwan and China to hold talks to ease tensions.

"Japan does not want to see military or political tensions rising regarding the issue involving Taiwan, and hopes that the issue will be solved peacefully through dialogue," Foreign Ministry spokesman Yoshinori Katori said in a statement. "Japan doesn't support any one-sided attempt from either side to change the current situation."

Beijing has repeatedly accused Chen of secretly plotting to declare formal independence — a step that it has said could lead to war.

The Foreign Ministry urged Washington "get a clear understanding of the serious and harmful nature of the secessionist activities by Chen Shui-bian."

The U.S. government should "take concrete actions to oppose secession activities of Taiwan independence," ministry spokesman Liu Jianchao said.

Washington has no formal diplomatic ties with Taiwan but maintains extensive unofficial relations and is obligated by federal law to see that Taiwan has the means to defend itself.

China has refused to have any contact with Chen or his pro-independence Democratic Progressive Party, and frequently targets both with threatening rhetoric.

The two governments have no official diplomatic relations, but trade, business and tourism ties are flourishing.

Beijing has hundreds of missiles aimed at Taiwan, just 100 miles off its southeastern coast. The mainland holds annual war games that include simulated assaults on offshore islands, and fired missiles into the sea near Taiwan during its 1996 presidential election in an effort to rattle voters.

The official China Daily newspaper said in an editorial Tuesday that Chen's moves "threaten to destroy peace and stability in the Asia-Pacific region." Beijing often uses the English-language newspaper to make announcements aimed at foreign audiences.