Seoul's Special Representative for Korean Peninsula Peace and Security Affairs, Lee Do-hoon, arrived in Washington on Wednesday.
This is Lee's first trip to the U.S. in five months.
According to Seoul's foreign ministry, Lee is to meet his American counterpart, Deputy Secretary of State Stephen Biegun, to discuss the situation on the Korean Peninsula.
It's believed that the North's recent actions are intended not only to spur Seoul to action but also to draw the attention of Washington.
Though there's not much room for the U.S. to revive the denuclearization talks, especially with a presidential election coming up later this year, the U.S. has softened its stance on cooperation between the two Koreas themselves.
Since the North's most recent provocations, Washington has said it supports South Korea's efforts to improve inter-Korean ties whereas before it was adamant that inter-Korean relations should go in step with progress in denuclearization.
While Seoul and Washington move to coordinate on North Korea, senior officials of the U.S. and China have also met on the issue.
Secretary of State Mike Pompeo and Chinese politburo member Yang Jiechi met in Hawaii Wednesday, mostly to discuss the rising tensions between their own countries.
But with Stephen Biegun also known to have taken part in the meeting, it's believed they also dealt with North Korea's recent actions.
Oh Jung-hee, Arirang News.