The United States is conducting sensitive negotiations to put new seismic devices in China to monitor Soviet underground nuclear tests, administration and congressional sources said yesterday.

The seismic facility, which would be similar to one that became operational last year in Norway, could help verify Soviet compliance with treaties that currently limit and could eventually ban underground nuclear tests, according to the fiscal 1987 Department of Energy (DOE) budget request to Congress.

A China-based facility would strengthen U.S. capabilities to detect Soviet tests and determine their size when carried out at the Semipalatinsk test site in East Kazakhstan, according to experts outside the government. Chinese territory lies roughly 350 miles from the Semipalatinsk site. The closest seismic facility to the main Soviet test site now is in Norway, roughly 4,000 miles to the northeast.

State and Defense Department officials yesterday refused to comment on the negotiations with China or the proposed facility, which were disclosed in the unclassified DOE budget document delivered to Congress two weeks ago.

A spokesman for the Defense Advanced Research Projects Agency, which operates the Norwegian seismic array in cooperation with the Oslo government, said the China project "is a Department of Energy matter and must be discussed with them."

Late yesterday afternoon, a DOE spokesman said, "We don't have any comment on that subject."

"In fiscal 1986," according to DOE's fiscal 1987 budget document, "negotiations began with the People's Republic of China (PRC) on a cooperative effort to culminate in the installation of a regional seismic array in the PRC."

Construction of the facility would begin next year, but only "after the U.S. and the PRC have reached agreement on the array installation," according to the DOE presentation. The Soviet Union last summer announced a unilateral halt to underground testing and futilely urged the United States to follow suit. Moscow recently announced that it would continue its moratorium until the United States conducts its next test, scheduled for late April.

The Norwegian seismic facility, believed to be the same type planned for China, has sharply increased U.S. monitoring capabilities.

On July 11, 1985, according to a Pentagon official, the Norwegian facility recorded a seismic signal from a Soviet explosion of less than one kiloton at Semipalatinsk. That Soviet test, equivalent to less than 1,000 tons of TNT, was of such a low yield that it was not picked up by a less-capable Swedish monitoring system and thus never publicly announced until disclosed by Pentagon officials in congressional testimony.

The Norwegian facility and a similar one being negotiated with Finland are 1,500 miles from Novaya Zemlya, an island in the Barents Sea above the Arctic Circle. Before the mid-1960s, it was the prime site for Soviet underground tests and still is used once or twice a year by the Soviets explode their largest shots.

The U.S. Air Force Technical Applications Center (AFTAC) has older, less sophisticated seismic detectors in about 35 countries around the world including Turkey. An AFTAC site in Iran was closed after 1979, when the shah fled the country.

Although the Reagan administration has acted to install the sensitive, multimillion-dollar modern seismic arrays in key countries surrounding the Soviet Union, it has continued to press for on-site monitoring of nuclear tests as the only way to verify the 1974 treaty signed with Moscow limiting underground tests to 150 kilotons.

President Reagan has also told Soviet leader Mikhail Gorbachev that he would not consider resuming negotiations to end nuclear tests without first obtaining sharp reductions in existing nuclear weapons. Talks on a comprehensive test ban, which began in the mid-1960s under the Kennedy administration, were suspended by the Carter White House after the Soviet invasion of Afghanistan.

The Reagan administration has refused to reopen those talks, focusing instead on getting new on-site monitoring as a condition to ratifying the threshold test ban agreement.

Gorbachev, for his part, has made progress toward ending nuclear tests as one of the goals of the next summit meeting. Last week he said that a Soviet moratorium on nuclear tests, which began last August and was scheduled to end this month, would stay in effect until the United States holds its next test. Meanwhile, the Soviets have continued preparations to resume underground test shots, according to Pentagon officials.

Last week, Reagan renewed an earlier offer to allow Soviet scientists to observe the next U.S. nuclear test, planned for the third week in April.