The United States will work with South Korea to find ways to support Seoul's indigenous fighter jet development program, even though some technologies remain "unavailable for export," a Pentagon spokesman said Wednesday.

The remark is seen as reaffirmation of the existing U.S. position that it is difficult to accept South Korea's request for the transfer of four key American technologies necessary for Seoul's "KF-X" indigenous jet fighter development project.

"The U.S. continues to support Korean programs through the transfer of many of our most sensitive defense technologies.

However, there is a very small group of technologies that continue to be unavailable for export," Army Lt. Col. Joe Sowers, a Pentagon spokesman, told Yonhap News Agency.

"The U.S. will work closely with Korea to find ways in which it can continue to not only support the development of Korea's indigenous fighter, but other programs as well," he said without elaborating.

It is the first time the Pentagon has commented on the issue.

Last week, the South Korean Defense Minister asked the U.S. to reconsider its decision not to accept the technology transfer request when he met with U.S. Defense Secretary Ash Carter in Washington, but Carter turned down the request.

The two sides agreed only to establish an interagency working group on defense technology cooperation.

The Korean Fighter Experimental project, under which South Korea is to produce 120 combat jets, hit a snag after the U.S. Department of State in April refused to grant permission for U.S.-based Lockheed Martin's export of four out of the 25 fighter jet technologies it has promised Seoul.

The defense ministers' talks last week came on the sidelines of South Korean President Park Geun-hye's visit to Washington. She also paid a visit to the Pentagon, attended a full honor parade and held talks with Carter.

"President Park's visit to the Pentagon was an opportunity to demonstrate the closeness and strength of the alliance after North Korea's recent provocative behavior," Cmdr. Bill Urban, a Pentagon spokesman, said in response to queries from Yonhap.

The spokesman also said that the U.S. and the South take the "North Korean nuclear and missile threat seriously and maintain strong bilateral coordination to deter, respond to, and if necessary defeat, this threat."

"We know that Pyongyang is continuing to develop its nuclear and missile capabilities. We have not seen North Korea test or demonstrate the ability to miniaturize a nuclear weapon and put it on an ICBM, but prudence warrants that we plan for the worst," he said.

Urban also noted that South Korea is in the process of securing major capabilities necessary to develop its own Kill-Chain and Korean Air Missile Defense systems that will be interoperable with the U.S. systems.

On the possible deployment of the THAAD (Terminal High Altitude Area Defense) system to South Korea, the spokesman repeated the existing U.S. position that it has made no decision on the issue.

"We have made no final decisions regarding the deployment of a U.S. THAAD unit to the Republic of Korea. Any decision would be made only after close consultation with our ROK allies," Urban said.

"The United States is committed to working with the Republic of Korea to develop a comprehensive set of Alliance capabilities to counter the growing North Korean ballistic missile threat," he said. "U.S. military capabilities on the Peninsula are intended to help defend the ROK and U.S. forces on the Korean Peninsula against the evolving DPRK threat." (Yonhap)