New South Korean president Moon Jae-in expressed surprise and "shock" that the South Korean Defense Ministry failed to inform him that four more launchers for the U.S.-built THAAD anti-missile system had been brought into the country without his knowledge.

Moon had expressed serious reservations about the deployment of the system and said the additional deployment would be under review.

Reuters:

South Korean President Moon Jae-in has ordered a probe after the Defence Ministry failed to inform him that four more launchers for the controversial U.S. THAAD anti-missile system had been brought into the country, his spokesman said on Tuesday.

The Terminal High Altitude Area Defense (THAAD) system battery was initially deployed in March in the southeastern region of Seongju with just two of its maximum load of six launchers to counter a growing North Korean missile threat.

During his successful campaign for the May 9 presidential election, Moon called for a parliamentary review of the system, whose deployment has also infuriated China, North Korea's lone major ally.

"President Moon said it was very shocking" to hear the four additional launchers had been installed without being reported to the new government or to the public, presidential spokesman Yoon Young-chan told a media briefing.

Moon had campaigned on a more moderate approach to Pyongyang, calling for engagement even as the reclusive state pursues nuclear weapons and ballistic missile programs in defiance of U.N. Security Council resolutions and threats of more sanctions.

The U.S. military in South Korea did not have immediate comment on Moon's comments. The South Korean military also did not immediately comment.

CHINA TENSIONS EASING

Moon's order of a probe into the THAAD launchers came amid signs of easing tensions between major trading partners South Korea and China.

South Korea's Jeju Air said on Tuesday China has approved a plan to double its flights to the Chinese city of Weihai from June 2.

China has been incensed over the THAAD deployment, fearing it could give the U.S. military the capability of seeing into its own missile systems, and could open the door to a wider deployment of the system, possibly in Japan and elsewhere, military analysts say.

China has denied it had discriminated against South Korean companies, which have faced product boycotts and bans on Chinese tourists visiting South Korea.

A Korean-Chinese joint drama “My Goddess, My Mom" starring South Korean actress Lee Da-hae, whose broadcast had been indefinitely delayed in China, was told by its Chinese partner recently that it will soon be aired, according to JS Pictures, Lee's agent.

You can understand Moon's concern about additional THAAD launchers when viewed in the context of his developing relationship with the Chinese.  His "reset" with China is going fairly well, but so far, it's been limited to mostly symbolic gestures.

China's intense opposition to the THAAD deployment threatens to upend his policy.  There is a legitimate question whether THAAD can realistically stop North Korea from successfully targeting the South with a nuclear missile if Kim decides on launching multiple weapons.  Moon may decide that not offending China takes precedence over the possibility that THAAD may work in the unlikely – but possible – event that the North decides on nuclear war.  

It's not clear if the additional launchers were part of the original THAAD deployment.  Even if they were, Moon may be looking for an excuse to severely limit or eliminate the deployment in deference to China.  That would send the wrong message to North Korea, which continues to issue wildly bellicose statements nearly every day about going to war.