South Korea's spy chief reportedly visited Washington over the past weekend to coordinate the allies' positions ahead of high-level talks between the United States and North Korea.

According to a source in Washington Thursday, National Intelligence Service Director Suh Hoon arrived in the U.S. capital on Sunday and met with Central Intelligence Agency chief Gina Haspel.

The spy chiefs are thought to have exchanged intelligence on the movements of North Korea in order to facilitate progress in the denuclearization talks between Washington and Pyongyang.   

Kim Yong-chol, a top aide to North Korean leader Kim Jong-un, arrived in Washington on Thursday for talks with U.S. Secretary of State Mike Pompeo to arrange a second summit between their leaders.