Jan. 30 (UPI) -- U.S. Defense Secretary James Mattis and South Korea's Defense Minister Han Min-koo exchanged a phone call to discuss a joint response to North Korea provocations, and a plan to move forward with the deployment the U.S. missile defense system THAAD.
The phone conversation, held in Seoul on Tuesday morning, comes a day after U.S. President Donald Trump and South Korea's acting president and Prime Minister Hwang Kyo-ahn exchanged a phone call during which the two sides reaffirmed the bilateral alliance but did not discuss pending issues that include increased military burden sharing.
Mattis and Han spoke for about 30 minutes on the need to "strengthen a response to North Korea's nuclear and missile threats," Yonhap reported.
Mattis reportedly said the importance of responding to the North Korea threat is the reason his first overseas trip is to Seoul in February, then to Tokyo, according to the report.
Seoul has been on alert since North Korea has repeated threats to test-launch an intercontinental ballistic missile.
One of the actions that are to take place is the deployment of THAAD on the peninsula, which is to be placed in position by July.
Seoul and Washington reached a bilateral decision to deploy THAAD in July 2016. At the time, the two countries agreed the missile defense system would be placed at its designated location by mid-2017.
Mattis' visit is expected to send a strong message to Pyongyang, according to Seoul's defense ministry.
On Monday, the U.S. State Department urged North Korea to refrain from provocations after 38 North, a Johns Hopkins University website dedicated to North Korea issues, showed recent images indicating Pyongyang may have restarted its plutonium-producing nuclear reactor.