The Republic of Korea (ROK) said on Monday the abrupt cancellation of U.S. Secretary of State Mike Pompeo’s trip to the Democratic People’s Republic of Korea (DPRK) is having an “effect” on a controversial inter-Korean liaison office it planned to open by this month.

U.S. President Donald Trump abruptly cancelled his top diplomat’s planned trip to the DPRK on Friday, publicly acknowledging for the first time that his effort to get Pyongyang to denuclearize had stalled since his summit with the DPRK leader.

ROK’s presidential Blue House spokesman Kim Eui-kyeom said on Monday that the cancelled visit “cannot be said to have zero effect” on the plan for the liaison office.

“We were thinking of the opening of the liaison office as part of a smooth series of schedules including Secretary of State Pompeo’s North Korea (DPRK) visit then the inter-Korean summit,” Kim said. “Now that a new situation has arisen, there is a need to inspect it again accordingly.”

The ROK has been building a liaison office just over the border in the DPRK, as part of efforts championed by the ROK President Moon Jae-in to improve ties between the two Koreas.

The office, which the ROK government said planned to open by August, had raised concern among opposition lawmakers, analysts and local media that the transfer of material for the office could violate U.N. and U.S. sanctions against the DPRK.

ROK’s Unification Ministry spokesman on Monday repeated its stance that all the material for the liaison office are for the office’s operation and the convenience of ROK personnel, and does not give any economic gain to the DPRK.

The spokesman added the two Koreas continue to discuss matters such as the timing of the office’s opening, after agreeing to open it “soon.”

“This issue is not something that our government can decide on its own, but must be discussed with the North,” said Kim, the Blue House spokesman. “I understand that there hasn’t been official discussion on how the North sees such situational changes, changes in conditions.”

DPRK state-controlled newspaper on Sunday accused the United States of “double-dealing” and “hatching a criminal plot” against Pyongyang, but did not mention Pompeo’s cancelled visit.

Since the June summit, the two sides have struggled to narrow differences over the Pyongyang’s nuclear weapons program.

Pyongyang has been calling for a declaration of peace as part of security guarantees designed to encourage it to abandon its nuclear weapons and ballistic missiles, while the Trump administration says a peace deal and other concessions will only come after more progress on denuclearization.

The inter-Korean summit slated for September remains on track, and President Moon’s role as mediator between the U.S. and the DPRK appears to have expanded after the cancelled visit, Blue House’s Kim told reporters on Sunday.