Chung arrived in the US capital this week to hold three-way consultations with his American and Japanese counterparts on recent developments with North Korea.

The visit came after North Korean leader Kim Jong-un threatened in a New Year's message to take "shocking actual action" and showcase a "new strategic weapon" in protest of stalled denuclearization talks with Washington.

US National Security Adviser Robert O'Brien had "great bilateral and trilateral meetings" with his Korean and Japanese counterparts on Wednesday, the White House National Security Council said on Twitter.

"Discussions covered Iran, DPRK-related developments and the importance of trilateral security cooperation," it said, referring to North Korea by its official name, the Democratic People's Republic of Korea.

South Korea has been looking at ways to support US security operations in the Middle East amid heightened tensions between Washington and Iran. Key among them is the possibility of deploying South Korean troops to the critical waterway in the Strait of Hormuz.

Washington has also emphasized the importance of trilateral security cooperation with Seoul and Tokyo in countering rising threats from North Korea and China.

Such insistence helped stop the two US allies from terminating their bilateral military intelligence-sharing pact in November.

Chung also met with Deputy Secretary of State Stephen Biegun, Washington's top envoy for denuclearization negotiations with North Korea.

The two "reaffirmed close US-ROK coordination on North Korea," the State Department said in a readout, using the initialism for South Korea's official name, the Republic of Korea.

They also "affirmed the enduring strength of the US-ROK alliance and reiterated their commitment to cooperation in the Indo-Pacific."

The two discussed recent events in the Middle East and ongoing coordination on global security issues, the department added. (Yonhap)