U.S. Ambassador to South Korea Harry Harris has emphasized that sanctions will remain in place until North Korea denuclearizes.

At a forum hosted by a local nonprofit think tank on Thursday, Harris said Seoul and Washington are in "complete agreement" on maintaining the sanctions.

The remarks come ahead of the second summit between the leaders of the U.S. and North Korea in Hanoi later this month, where they are expected to focus on fleshing out Pyongyang's steps towards denuclearization and Washington's corresponding measures. 

Harris credited President Moon Jae-in for his “tremendous efforts” to reach out to North Korea and lay the groundwork for lasting peace on the Korean Peninsula, while adding that the allies share the common goal of Pyongyang’s final, fully verified denuclearization. 

The U.S. ambassador also noted China's role in maintaining sanctions on the North, saying no progress would have been made on denuclearization negotiations without China's support.