South Korea's new Defense Minister Han Min-koo and U.S. Secretary of Defense Chuck Hagel held their first conversation by phone on Saturday and discussed the alliance between the two countries, the Pentagon said.

Hagel congratulated Han on his appointment, saying he looks forward to working with him to continue strengthening the alliance, the Pentagon said in a press release. Hagel initiated the call, according to the defense department.

Han, a former chairman of the Joint Chief of Staff, took office as South Korea's defense minister on June 30 after his predecessor Kim Kwan-jin left to take over as national security adviser for President Park Geun-hye.

Han and Hagel are scheduled to meet in Washington in October when the two countries hold annual defense ministers' talks. A key topic for the Security Consultative Meeting will be to determine when South Korea should retake the wartime operational control of its troops from the U.S.

South Korea is supposed to take back the control, known as wartime OPCON, in December 2015. But last year, Seoul asked for a delay, citing increased threats from nuclear-armed North Korea. The two sides are basically in agreement on putting off the transfer, and October's meeting will determine by how long it should be delayed.

Hagel also called Kim's predecessor, national security adviser Kim, and thanked him for his partnership while he was the minister of defense and indicated that he looks forward to working with his successor Han, the Pentagon said. (Yonhap)