Washington/Taipei, July 9 (CNA) The United States Department of State has approved a request by Taiwan for the recertification of its Patriot Advanced Capability-3 (PAC-3) air defense missiles, at an estimated cost of US$620 million.

In a statement Thursday, the U.S. Defense Security Cooperation Agency (DSCA) said Congress had already been notified of the possible sale.

According to the DSCA, which is under the Department of Defense that oversees the U.S. Foreign Military Sales (FMS) program, Taiwan has asked to buy parts to refurbish its PAC-3 missiles to support an operational life of 30 years.

The package includes the test and repair of the missile system, such as Stockpile Reliability Testing (SRT) and Field Returns, Ground Support Equipment (GSE) component level parts, and other related elements of logistics support, at an estimated cost of US$620 million, the DSCA said.

The primary contractor will be Lockheed Martin, a U.S.-based aerospace, defense, arms, security, and advanced technologies company, the agency said.

"This proposed sale is consistent with U.S. law and policy as expressed in Public Law 96-8," the statement read.

Public Law 96-8 pertains to the Taiwan Relations Act, which was passed by the U.S. Congress in 1979 with an aim to providing a strong foundation for Taiwan-U.S. cooperation in the absence of formal diplomatic ties.

"This proposed sale serves U.S. national, economic, and security interests by supporting the recipient's continuing efforts to modernize its armed forces and to maintain a credible defensive capability," the agency said.

"The proposed sale will help improve the security of the recipient and assist in maintaining political stability, military balance, and economic progress in the region."

On Friday, the Ministry of Foreign Affairs (MOFA) said it welcomed the State Department's decision to approve Taiwan's request for recertification of the PAC-3 missiles, which were purchased from the U.S. years ago.

Taiwan will continue to seek close security partnership with the U.S., while contributing to long-term peace and stability in the Indo-Pacific region, MOFA said.