The defense chief of the United States plans to visit South Korea in early April for talks with his South Korean counterpart on pending security and alliance issues, sources here said Wednesday.

U.S. Secretary of Defense Ashton Carter is expected to come here early next month as the destination of his first bilateral visit since taking office last month," a Seoul source said, adding his itinerary will also include Japan.

"Seoul and Washington have made a significant progress in pushing for Carter's trip here," another source said. "A wide range of bilateral issues will be dealt with at the ministers' talks."

In a statement, Seoul's defense ministry said earlier in the day that Carter and South Korean Defense Minister Han Min-koo "agreed to exchange opinions on the security situation and pending bilateral issues after meeting in the near future."

The agreement was made in a dialogue between the two over the phone, during which Carter and Han also "agreed to closely cooperate for the development of the relations and a stronger joint defense posture in the future," according to the ministry. 

In Washington, the Defense Department said that Carter and Han "highlighted the deep and enduring defense partnership" between the two countries. Carter also expressed gratitude for Han's "unwavering support following the attack" on the U.S. Ambassador to Seoul Mark Lippert, the department said in a statement.

The planned visit by the top U.S. defense official comes at a time when Seoul is divided over whether to allow the U.S. to deploy a THAAD (Terminal High Altitude Area Defense) missile defense battery on its soil, while officials of the two sides have said there have been no official consultations on the matter.

Supporters say the deployment would help better protect against North Korea's ballistic missile threats, while opponents claim it would inflame tensions with China and Russia as they see the move as a threat to their security interests.

During his confirmation hearing in February, Carter pledged to significantly beef up missile defense, including deploying more ground-based missile interceptors in California and Alaska, saying North Korean missiles could pose a "direct threat" to the country.

In 2006, he openly called for a pre-emptive strike on a North Korean long-range missile that was being readied for a test-launch, claiming that the risk of inaction in the face of North Korea's race to threaten the U.S. would be greater than the risk associated with a pre-emptive strike.

On Thursday, Gen. Martin Dempsey, chairman of the U.S. Joint Chiefs of Staff, is set to arrive here for a three-day visit for talks with his counterpart on boosting the bilateral alliance. (Yonhap)