The Pentagon has announced the deployment of an additional 800 troops to South Korea, along with combat tanks and other military hardware, as Washington seeks to counter any regional threats from North Korea.
Tuesday's deployment announcement came as U.S. Secretary of State John Kerry met in Washington with his South Korean counterpart, Yun Byung-se. Kerry used the meeting to assure Yun of Washington's commitment to South Korea's nuclear defense, in his words, "so that we are prepared to face any threat."
Kerry said the two diplomats are "deeply focused on the challenge of North Korea, particularly with events that have taken place in recent weeks" in Pyongyang.
His comments appeared to reference a recent political purge that included the execution of the uncle of North Korean leader Kim Jong Un.
The killing in December of Jang Song Thaek, a powerful member of the politburo, is seen by some Western analysts as a move by Kim to consolidate power, and by others as evidence of political instability within the North Korean hierarchy.