The State Department said yesterday that a U.S. inspection team found an extensive underground tunnel complex at a North Korean construction site suspected of being built to develop nuclear weapons, but the tunnels were empty and no work was being done.

The department spokesman, James P. Rubin, said the purpose of building the site was not clear from the inspection, but that "there is no basis to conclude that North Korea is in violation of the agreed framework" for preventing nuclear weapons development.

Under that framework, North Korea must halt nuclear weapons development in return for U.S. participation in a $5 billion program to supply fuel oil and build two new nuclear reactors of the safer, non-threatening light water variety. President Clinton must decide next month whether to certify whether North Korea is in compliance with that agreement.

Some U.S. officials have strongly suspected North Korea was renewing its nuclear weapons program at the massive underground site, near Kumchangri, since spy satellites detected a huge construction project there last year.

After an uproar in Congress last summer, the United States negotiated access to the site. But given how long negotiations dragged on over access, few experts expected the 14-person U.S. inspection team to find any evidence of nuclear weapons development there.

Rubin said another inspection is planned for next May, along with other visits "to fully remove our suspicions." He said construction was unfinished. He said the annual visits would provide information and be a "deterrent" against developing the site for nuclear weapons.

The inspection came just before a visit by Clinton's presidential envoy, former defense secretary William J. Perry, who led a high-level delegation to North Korea. Perry's group, which left Pyongyang yesterday and traveled to Seoul, spent four days in the North Korean capital.

Although Perry came with a letter from Clinton for North Korea's reclusive president, Kim Jong Il, he did not meet with the North Korean leader. Instead, he delivered the letter to Kim Young Nam, president of the presidium of the Supreme People's Assembly. He also met with Kang Sok Ju, the North's first vice minister of foreign affairs who negotiated the 1994 agreement with the United States.

North Korea has indicated its disappointment with the U.S. failure to lift economic sanctions after the 1994 agreement, but U.S. officials said before the Perry trip that the presidential envoy would not offer further incentives unless North Korea made further concessions or openings to the West.

One issue the United States, Japan and South Korea might seek is North Korean agreement to halt future missile tests. Last August, North Korea fired a missile into the Sea of Japan.