U.S. Defense Secretary Ashton Carter will arrive in South Korea on Thursday in a bid to reaffirm America’s commitment to countering North Korea’s evolving nuclear and missile threats and encourage U.S. troops here.

His scheduled visit has drawn keen attention as Carter and his South Korean counterpart Han Min-koo are expected to touch on the issue of the U.S.’ potential deployment of the Terminal High Altitude Area Defense system during their talks Friday.

Seoul officials said the THAAD issue was not included in the official agenda. But observers say discussion about the issue is unavoidable as it has emerged as a hot-button political issue amid China’s explicit opposition to it.

Mindful of repeated opposition from Beijing, Seoul has taken a cautious stance over THAAD, which Beijing argues could undermine its security interests. Seoul has so far maintained there have been “no official consultations between the allies, no request from the U.S. and no decision made.”

The agenda for the bilateral talks include strengthening the allies’ deterrence against North Korea’s nuclear and missile threats and developing follow-up measures to push for the conditions-based transition of wartime operational control.

Should the THAAD issue not be discussed during the talks, the issue could be touched on at the Korea-U.S. Integrated Defense Dialogue to be held mid-April in Washington, observers say.

After the talks between the two ministers, Han and Carter will visit the 2nd Fleet Command in Pyeongtaek, Gyeonggi Province where the wreckage of the ill-fated corvette Cheonan is on display. The Cheonan was sunken by a North Korean torpedo attack in March 2010, which killed 46 sailors.

Carter will be the first U.S. defense chief to visit the wreckage, Seoul officials said.

Carter will land in South Korea following a visit to Japan. His trip is focused on reaffirming the U.S.’ strategic rebalance toward the Asia-Pacific and strengthening security cooperation with Washington’s core allies of Seoul and Tokyo.

By Song Sang-ho (sshluck@heraldcorp.com)