Prime Minister Eisaku Sato, who won the 1974 Nobel Peace Prize for working out Japan's three-point non-nuclear policy, asked the United States in 1965 to use its nuclear weapons against China in immediate retaliation should a war break out between that country and Japan, according to newly declassified Japanese diplomatic documents.

In talks with Defense Secretary Robert McNamara in Washington, Sato also said it would be possible for the United States to put such an operation into action immediately from the sea — remarks that could be taken as tacit consent to bring nuclear arms into Japanese territory.

The revelation confirms that Sato, prime minister from 1964 to 1972, distrusted Beijing because he was asking the United States to be ready to launch a nuclear first strike.

The diplomatic documents are among a raft of roughly 30-year-old papers officially declassified Dec. 22 by the Foreign Ministry.