SEOUL, May 4 (Xinhua) -- Chung Eui-yong, top national security advisor for South Korean President Moon Jae-in, is currently staying in the United States ahead of the summit between the United States and the Democratic People's Republic of Korea (DPRK), local media reported Friday citing the Blue House of South Korea.

An unidentified Blue House official told local reporters that Chung made a closed-door visit to the United States at the request of the National Security Council of the White House to discuss the DPRK-U.S. summit.

The visit was not made open beforehand to the media at the request of the U.S. side, according to the Blue House official.

The official estimated that Chung would discuss with his U.S. counterpart a "big deal" about the DPRK-U.S. summit to resolve the Korean Peninsula's nuclear issue as well as the location of the summit, which he said is a small deal.

Chung's visit came a week after Moon and top DPRK leader Kim Jong Un held the third-ever inter-Korean summit at the border village of Panmunjom.

Days before the Moon-Kim summit, Chung visited Washington. Kim is forecast to meet with U.S. President Donald Trump in May or early June, but the location and the exact date for the first-ever DPRK-U.S. summit had yet to be determined.

Panmunjom recently emerged as one of candidate venues for the Kim-Trump summit.

Moon and Kim agreed to complete denuclearization and the turn of the current armistice agreement into a peace treaty by the end of this year. The Korean Peninsula remains technically at war as the 1950-53 Korean War ended with armistice.