SEOUL, Feb. 1 (Xinhua) -- Military chiefs of South Korea and the United States reaffirmed the two allies' defense posture against the Democratic People's Republic of Korea (DPRK)'s nuclear and missile threats, the Joint Chiefs of Staff (JCS) of South Korea said Wednesday.

The JCS said in a press release that Gen. Lee Sun-jin, the chairman of the JCS, had a telephone dialogue earlier in the morning with his U.S. counterpart Joseph Dunford.

It was the first phone talk among military chiefs of the two allies since the Trump administration was launched in January.

During the dialogue, Lee and Dunford agreed on further efforts to strengthen the "deep-rooted alliance" and the mutual trust, which the two countries have built up.

They assessed the currently urgent security situations, including the DPRK's nuclear and missile programs, vowing to further build up a joint defense posture against Pyongyang.

The phone talks came a day after the defense ministers of the two countries had a telephone dialogue ahead of new U.S. Defense Secretary James Mattis' scheduled visit to South Korea on Thursday and Friday.

South Korean Defense Minister Han Min-koo is set to hold the bilateral talks with Mattis on Friday. The Pentagon head is scheduled to pay a courtesy call on Thursday to Prime Minister Hwang Kyo-ahn, who is serving as South Korea's serving president.

During the talks, Gen. Lee reportedly stressed the importance of implementing the U.S. extended deterrence.

The JCS was quoted as saying that Lee and Dunford discussed the deployment of U.S. strategic assets as part of measures to enhance the implementation of the U.S. extended deterrence.

South Korea and the United States held their first joint defense cooperation talks, called the Extended Deterrence Strategy and Consultation Group (EDSCG) meeting, in Washington in December.

During the meeting, Seoul allegedly urged Washington to deploy U.S. strategic assets on a regular rotational basis, but Washington has yet to determine on it.

The U.S. military temporarily sent its strategic assets, including nuclear-capable B-52 and B-1B bombers, to South Korea last year following the DPRK's fourth and fifth nuclear tests in January and September respectively.