The United States said Thursday it was an "inexcusable mistake" to ship a live anthrax sample to an American military base in South Korea, promising to consult the Asian ally in case of a similar shipment in the future.
  

"This was a mistake. As the secretary said, it was a serious mistake. It should never have happened. It's an inexcusable mistake. We're taking the actions to correct it," Undersecretary of Defense for Acquisition, Technology and Logistics Frank Kendall told reporters.
  

Kendall made the remark during a briefing on the outcome of an investigation into the erroneous shipments of live anthrax samples to 86 laboratories in 20 states, Washington, D.C., and seven foreign countries, including South Korea's Osan Air Base in Pyeongtaek, south of Seoul.
  

"It was an unintended delivery. It was anthrax that was believed to be inactivated and not live and not able to be grown went to an air force base in Korea to a laboratory on that base for testing there. I don't think it ever would have gone anywhere else," Kendall said.
  

The official stressed that the U.S. had intended to deliver inactivated anthrax spores as part of efforts to make sure that the country is "in a position to protect people in the case of an anthrax attack in Korea or anywhere else if we ship it."
  

Kendall said the U.S. has no intent to resume anthrax shipments, but even if it does, it would consult Korea.
  

"I can't speculate about what may happen in the future. Anything that we did do, I can assure you, though would be done in consultation with the Korean government, and there is a task force now working with the Korean government to investigate the specific events that happened at Osan," he said.
  

When the case surfaced in late May, U.S. Forces Korea said the sample delivered to Osan was destroyed after it was suspected of being live, but 22 civilian and military personnel "may have been exposed" and were given emergency treatment, though none of them showed any signs of exposure.
  

It said the sample was brought in for a training exercise aimed at testing field equipment and new systems designed to identify toxins and pathogens. North Korea is believed to be capable of cultivating various types of biological agents, such as anthrax, and producing them into biological weapons.
  

On Thursday, the U.S. Department of Defense unveiled a report after a 30-day investigation into the case.
  

It blamed "inherent deficiencies" in protocols for killing anthrax spores, claiming that "a single root cause" for the accident could not be identified and that the Department of Defense personnel correctly followed their own protocols -- albeit lacking -- to make anthrax samples inactive before shipments.
  

"A key finding by the committee is that there is insufficient technical information in the broader scientific community to guide the development of thoroughly effective protocols for inactivation of spores and viability testing of (Bacillus anthracis)," the report said.
  

"This has contributed to the creation of protocols that do not completely or permanently sterilize BA with gamma irradiation. The absence of this critical information is a scientific communitywide problem and needs to be addressed with irradiation standards and viability testing procedures," it said.
  

The report said that the investigative committee found "inherent deficiencies" in protocols for the production of inactive spores that could lead to non-sterile products for three phases -- radiation dosing, viability testing and contamination prevention.

  
The report said that the anthrax samples contained low numbers of live spores and "did not pose a risk to the general public."

Nonetheless, the shipment of live samples is a "serious breach of regulations," the report said.
  

Thursday's report only made a series of usual recommendations, such as enhancing quality control programs at Department of Defense laboratories, making labs follow a common procedure for irradiation and viability testing, and establishing quality control procedures for inactivation and viability testing of anthrax spores.
  

U.S. Defense Secretary Ashton Carter apologized for the incident and promised to take proper actions to prevent a recurrence when he met with South Korean Defense Minister Han Min-koo on the sidelines of an annual security forum in Singapore.
  

South Korea and the U.S. have also formed a joint working group to investigate the incident.
  

The case has also given rise to calls for revising the Status of Forces Agreement, which stipulates the legal rights and obligations of some 28,500 American troops stationed in South Korea, in a way that requires the U.S. military to notify the host nation in advance before bringing in such hazardous materials.
  

Anthrax is a lethal disease caused by Bacillus anthracis, but the term is commonly used to refer to the causative agent itself.

In 2001, anthrax-laced letters were mailed to U.S. news media and Senate offices and killed five people.
  

Following the Thursday report, USFK vowed efforts to ensure its biological defense programs with South Korea be continued in a safe and effective manner.
  

"Alliance biological defense programs are designed to enhance Alliance readiness and defensive capabilities in the face of a very real and significant biological threat," USFK commander Gen. Curtis M. Scaparrotti was quoted as saying in a separate USFK press release in Seoul.
  

Under the program, the allies conduct annual exercises to enhance combat readiness against North Korea's biochemical weapons.
  

"The establishment of the ROK-U.S. Alliance's Biological Defense Cooperation Joint Working Group will ensure continued cooperation on biological defense programs," Scaparrotti said. (Yonhap)