By Alex Jensen

SEOUL

Seoul’s security chief will head to the U.S. this week with an “undisclosed” message for Washington from North Korea, local officials revealed Wednesday.

National Security Office head Chung Eui-yong will leave for the U.S. on Thursday to share the secret communication with American officials, according to South Korean presidential office staff cited by Yonhap News Agency.

Chung met North Korean leader Kim Jong-un in Pyongyang on Monday, having traveled as a special envoy for the South’s President Moon Jae-in.

The security chief announced on his return to the South Tuesday that he had reached several breakthrough agreements with Pyongyang – including the North’s preparedness to discuss denuclearization with the U.S. and a planned third ever inter-Korean summit in late April.

It remains uncertain what exactly the North would demand in return for backing away from its development of nuclear weapons, with Pyongyang’s rhetoric consistently condemning the presence of American military hardware and around 30,000 troops on the Korean Peninsula.

The U.S. has long stressed that North Korea must demonstrate its willingness to denuclearize before being rewarded with dialogue.

Washington has led many of its own sanctions in addition to global punitive measures aimed at reining in Pyongyang’s nuclear ambitions.

U.S. President Donald Trump told reporters in the wake of this week’s inter-Korean deal that he thinks the North is “sincere because of the sanctions”.

Meanwhile, Washington’s State Department confirmed further sanctions Tuesday local time after concluding that North Korea murdered Kim Jong-un’s half-brother using a chemical warfare agent, VX. Kim Jong-nam died suddenly at an airport in Malaysia last year after being approached by two women, who were later arrested.