China yesterday broke off talks with Vietnam which have failed to ease tension on the border between the two former allies.

Chinese Vice Foreign Minister Chung Hse-tung said in Hanoi that the Vietnamese were "using the talks to camouflage violence and using violence to undermine the talks," according to the official New China News Agency. The announcement came a day after Hanoi charged Peking with deploying large numbers of heavily armed troops near its border.

Adjournment of the talks, that began Aug. 8, deprive the volatile situation on the Sino-Vietnamese border of an important diplomatic safety valve. It could also aggravate the already full-scale conflict going on between Vietnam and China's close ally, Cambodia.

Since a bloody scuffle reportedly took nine lives at the Sino-Vietnamese "Friendship Pass" border area Aug 2, there have been few reports of serious border clashes. Both Peking and Hanoi have seemed preoccupied by the serious situation on Vietnam's border with Cambodia. The Cambodians, backed by Chinese arms and weapons, anticipate renewed fighting with Vietnamese troops when heavy rains slacken in a few weeks. The Vietnamese are already inside Cambodian territory.

Chung, although leaving open the possibility that the Hanoi negotiations might resume, said the "deterioration of the talks to such an extent in less than two months' time is correlated to the escalation of the anti-China activities of the Vietnamese authorities over the same period."

An official Vietnam News Agency dispatch this morning disputed the Chinese account of the negotiations and said Hanoi's delegates had asked yesterday that the talks continue.

"In face of such good-willed attitude of our side, the Chinese side has accused us of "closing the negotiation door," of 'sabotaging the negotiation." This is something beyond everyone's understanding," the agency quoted the Vietnamese delegation leader as saying.

An official Chinese agency report this morning said, however, that talks had broken off without any agreed resumption date. Vietnamese delegation chief Hong Bich Son said he hoped the two sides would meet again at an early date, the Chinese agency said. It quoted Chung as replying: "The day will eventually come when we shall meet again."

Peking and Hanoi have been at odds for at least two years, as border tensions between Vietnam and the Chinese-backed Cambodians have increased and as the Vietnamese have continued close relations with China's arch foe, the Soviet Union. Disputes among these communist powers in Southeast Asia arose soon after their common enemy. The United States, withdrew in 1975 when the pro-Western governments in Vietnam and Cambodia collapsed.

The animosity between China and Vietnam, now the two most heavily armed Asia nations, did not break into the open, however, until earlier this year when more than 160,000 ethnic Chinese residents of Vietnam poured across the border into southern China.

Welfare officials in southeast Asia ages in Vietnam and what appears to be widespread discrimination against them in jobs and schooling brought on by the growing Peking-Hanoi split.

Peking said the Vietnamese were persecuting the ethnic Chinese and forcing them into China to disrupt China's southern provinces. Hanoi said the refugees were being lured into China by Peking in order to weaken Vietnam in its flight with Cambodia.

Chung accused Hanoi yesterday of expelling, abducting, arresting and even killing Chinese nationals at border passes and in its capital Hanoi" according to the Chinese news agency. Hanoi has labeled such charges in the past as "sneer fabrications" and "outrageous slanders."

As the Vietnamese side has simply no intention to discuss and solve problems, and has closed the door to negotiations, it is impossible for the talks to go on," Chung said yesterday.

The official Vietnam-News Agency said Monday that "the Chinese side has deployed more armed forces in the provinces across from the Vietnamese border, . . . whole division of infantry equipped with thousands of artillery pieces, hundreds of tanks and armored cars, and hundreds of fighter planes are poised in the two military regions bordering Vietnam. . . . Various type of vessels are carrying out provocation in Vietnamese territorial waters, the agency said.

Although diplomatic sources here have said Chinese forces near the border were reinforced several months ago, they say they know of no significant recent troop movements. There have been an unusual number of Chinese naval vessels maneuvering off the south China coast lately but Western naval experts say the Chinese appear to conduct naval maneuvers regularly at this time of year.

Peking has attacked what it calls Hanoi's effort to "spread the rumor about China's intent to attack Vietnam." It has accused the Vietnamese in turn of "beefing up their military strength" to attack not China, but Cambodia to the south-west.

The latest talks in Hanoi began after lower-level discussions failed to end the masse xodues of ethnic Chinese from Vietnam. The two sides have continued to insist on their own versions of the refugees' status and plight, thus creating an apparently hopeless deadlock.

Hanoi says that almost all the estimated 1.8 million ethnic Chinise in Vietnam are Vietnamese citizens, by longstanding practice or individual choice. It rejects Peking's description of them as "Chinese nationals" undergoing persecution.

Peking says that Hanoi agreed years ago to consult on now its Chinese residents would be labeled and jointly rejected with China an attempt by the then pro-Western government in South Vietnam to declare all its Chinese residents to be Vietnamese citizens in 1955.