The Soviet Union yesterday labeled H. R. Haldeman's assertions of a Soviet plan to launch a nuclear strike against China with U.S. assistance "a lie from beginning to end."

The statement, issued by Tass, the official Soviet news agency, called the account by the aide to former president Nixon "provocative invention." It reports that both former secretary of state William P. Rogers and then-national security adviser Henry Kissinger "most resolutely refuted these inventions."

Tass adds, "nevertheless, some American newspapers continue spreading the fabrication."

Haledman, in his account of his years in the Nixon White House as the president's top personal assistant, wrote that Nixon turned down a Soviet proposal in 1969 that the two superpowers together attack and destroy China's new nuclear weapons manufacturing facilities.

Tass declared that "in reality, any Soviet proposal of this kind was out of the question," saying it was against Soviet foreign policy.

"It is also known that the Soviet Union proposed to China concluding a special treaty on the nonuse of force" around the same time, Tass says.

Informed Western diplomatic sources here speculated that such an initiative on the part of the Soviets was "possible" in 1969. At that time, the sources pointed out, the Chinese nuclear facilities were believed to be poorly defended and vulnerable to attack. The Soviets had moved strong forces to their frontier with China ofter a series of border clashes.

One source here asserted that there has been speculation in the U.S. intelligence community that the Poltburo were asked to vote on such an operation in 1969 and vetoed it. There is no way to measure the veracity of such a claim, except to record that the source inists that the speculation predated Haldeman's assertions by many months.

In general, the official Soviet view of the Watergate scandal has been that it was a sinister effort to victimize Nixon because he had achieved detente with the Soviet Union, angering powerful, conservative elements in the American power structure.