The two Koreas earlier agreed to open the liaison office in the North's border town of Kaesong to foster cross-border exchanges, and it was expected to be launched within August. But it has been delayed with no particular date for its launch yet to be fixed.

Earlier, a Cheong Wa Dae official said that the schedule for the liaison office launch will likely be finalized when a South Korean presidential envoy visits North Korea on Wednesday to discuss preparations for what will be a third inter-Korean summit this year.

Critics in Washington have voiced concerns that the operation of the office could run counter to multilayered sanctions the international community has imposed against the North, a discomfort many here suspect might have been behind the current delay.

The US appears to be worried about South Korea speeding up its efforts to improve its ties with North Korea at a time when its denuclearization talks with the North have been stalemated in recent months.

Washington has said that progress in inter-Korean relations should be tied to progress in the denuclearization process and that sanctions should remain in place until Pyongyang takes meaningful steps in giving up its nuclear weapons program.

Baik reiterated the Seoul government's stance that the issues of denuclearization and inter-Korean relations cannot be sought separately, assuring that they are currently moving forward in a virtually beneficial manner.

Meanwhile, the spokesman said that he understands that the North is making diverse preparations for the upcoming 70th anniversary of its state establishment on Sept. 9, including a military parade. But he said that there has been no invitation from the North for South Korean people to join the ceremony. (Yonhap)