A delegation of American diplomatic, military and intelligence officials led by Undersecretary of State Thomas R. Pickering met with Foreign Ministry officials here today to offer the U.S. government's official explanation of how it mistakenly bombed China's embassy in Belgrade on May 7, killing three Chinese journalists.

Pickering and representatives of the CIA, the Defense Intelligence Agency and other agencies entered a series of closed-door meetings this morning and were scheduled to meet with Chinese Foreign Minister Tang Jiaxuan and several of his deputies. U.S. officials offered to come to Beijing weeks ago but Chinese officials delayed the meeting, asking that a higher-ranking official such as National Security Adviser Samuel R. "Sandy" Berger come instead of Pickering, said a diplomat in Beijing.

Chinese government-controlled newspapers have declared that the bombing was a deliberate act of aggression meant to test China's resolve and to keep the country weak, a position still held by many Chinese. U.S. officials have said the bombing was a tragic mistake caused by the use of outdated maps, and President Clinton has apologized.

The Chinese Foreign Ministry has demanded that the United States lead a "comprehensive, thorough, just and responsible" investigation of the bombing, and that it "punish the perpetrators." The ministry also reserved the right to take further action if it is dissatisfied with America's answers. In response, Pickering will present the Chinese with a litany of U.S. errors.

"The report goes through, in a very detailed manner, where the mistakes occurred and how they occurred," said a diplomat in Beijing.

It remains unclear whether anyone will be punished, and the issue will likely remain a key Chinese demand. There are no plans to publicly "identify any individual who is at fault," the diplomat said, adding that "it's an institutional issue and any corrective measures that need to be taken should be done institutionally."

Pickering's visit is intended to help pull Sino-American relations out of one of its worst downturns in two decades. China has suspended high-level military contacts with the United States, halted cooperation on nuclear proliferation issues, ended its dialogue with the United States on human rights, and postponed negotiations on entering the World Trade Organization. Conservatives inside the Chinese government and military have also used the incident to demand higher military expenditures.

But it is unlikely that any report can satisfy most Chinese citizens, who find it impossible to believe that the world's high-tech superpower, with its network of spy satellites and its laser-guided smart bombs, could have made such a low-tech mistake.

Although Chinese leaders have demanded a detailed account of the bombing, Pickering's message could leave them in an awkward position.

"The explanation is quite similar to what the U.S. government said already. The key point is how the Chinese government will take its stand, and how it will explain it to the Chinese people," said a Chinese foreign policy adviser. "The ball is on the side of the Chinese government."

The explosion of nationalist sentiment after the bombing, including protests in more than a dozen cities, came at an opportune time for Chinese leaders. They were skittish about the possibility of demonstrations marking the 10th anniversary of the 1989 military crackdown on democracy demonstrators near Tiananmen Square. They view nationalism as a useful tool for deflecting criticism from themselves, crucial at a time when economic growth has slowed and reforms have increased layoffs.

A few days after the bombing, the Communist Party began trying to channel the anger toward productive causes, arguing that patriotic citizens should work hard and cooperate with Americans because doing so can make China strong -- and a strong China can't be humiliated by the United States again.

President Jiang Zemin and Premier Zhu Rongji have staked their political futures on maintaining good relations with the United States. China's massive exports to the United States, and continued U.S. investment and technology transfers are linchpins of their development strategy.

CAPTION: Chinese citizens tour an area exhibiting the busts of the three journalists killed when NATO bombs struck the Chinese Embassy in Belgrade on May 7.