The top diplomats of South Korea and the U.S. held talks in Washington Thursday and agreed to maintain close cooperation in their efforts to denuclearize North Korea.

U.S. State Department spokeswoman Heather Nauert said in a statement that the diplomats reaffirmed the ironclad alliance between the two nations and pledged to maintain close coordination to ensure the final, fully verified denuclearization of North Korea.

Foreign Minister Kang Kyung-wha and Secretary of State Mike Pompeo are thought to have discussed issues related to North Korean leader Kim Jong-un's possible trip to Seoul and a second U.S.-North Korea summit. 

Meanwhile, the two allies' working group launched last month is seeking to hold a video conference soon to further align their approaches on the denuclearization process and implementation of North Korea sanctions.