BEIJING, China (CNN) -- China on Wednesday expressed its "grave concern and strong displeasure" over what the United States said was an accidental shipment of ballistic missile components to Taiwan.
A U.S. Defense Department image shows the missile components it says were accidentally shipped to Taiwan.
China has asked the United States "to thoroughly investigate this incident, and report their findings to the Chinese side in a timely, truthful and detailed manner," Foreign Ministry spokesman Qin Gang said in a statement on the ministry's Web site.
"We once again remind the United States to abide by the Sino-U.S. joint communique of August 17, and cease arm sales to Taiwan and contact with the Taiwanese military, in order to avoid damaging the peace and stability across the Taiwan Straits and the healthy development of Sino-U.S. relations," the statement said.
The reaction comes a day after U.S. Secretary of the Air Force Michael Wynne announced the accidental shipment, which happened in the fall of 2006. The mistake was not discovered until last week, he said.
Four nose cone fuses for intercontinental ballistic missiles were shipped to Taiwan instead of the the helicopter batteries it had ordered, Wynne said.
He said the fuses, intended for a Minuteman strategic nuclear missile, were returned to the United States after the mistake was discovered.
"There are no nuclear or fissile materials associated with these items," Wynne said. Watch Wynne's account of problem »
The items, which had been held in storage in Taiwan, were shipped from the F.E. Warren Air Force Base in Wyoming to the Defense Logistics Agency warehouse at Hill Air Force Base in Utah, he said, and then on to Taiwan. An investigation is under way to determine what happened and how, Wynne said.
Speaking at Tuesday's news conference, Principal Deputy Undersecretary of Defense for Policy Ryan Henry emphasized how "disconcerting" the mistake was to Defense Secretary Robert Gates, who has "made it a personal priority to effectively deal with this matter," he said.
"In an organization as large as the DOD ... there will be mistakes, but they cannot be tolerated in the arena of strategic systems, whether they are nuclear or only associated equipment, as in this case," Henry said.
Gates has directed the Air Force and Navy secretaries to "conduct a comprehensive review of all policies, procedures, as well as a physical site inventory of all nuclear, and nuclear-associated materials and equipment across their respective programs," Henry explained.
He said that a preliminary investigation of the items did not show that they had been tampered with, and he lauded the Taiwanese authorities for how "responsibly" they handled the incident.
The technology for the nose cone fuses is "quite dated," Henry said, specifying that they were from a system built in the 1960s.
Under the Taiwan Relations Act, the United States pledged to sell Taiwan arms to defend it from attack.
Beijing has claimed the island as its own since their split at the end of the Chinese civil war in 1949.
Despite the incident, U.S. policies toward Taiwan remain unchanged, the officials said.
It is the second nuclear-related mistake involving the Air Force in less than a year. In August, a B-52 bomber mistakenly carried six nuclear warheads from North Dakota to Louisiana. A six-week investigation uncovered a "lackadaisical" attention to detail in day-to-day operations at the air bases involved in the incident.
The Air Force said it relieved four officers, including three colonels, and a number of other personnel lost their certification to handle sensitive weaponry. E-mail to a friend