South Korea will re-evaluate the opening of a joint liaison office with North Korea, a presidential official said Monday, indicating a possible delay amid an apparent stumbling block in U.S.-North Korea talks on ending North Korea's nuclear ambitions.

The remarks came three days after U.S. President Donald Trump called off a scheduled trip by his State Secretary Mike Pompeo to the communist North.

"The opening of the liaison office had been planned under smooth progress (in denuclearization efforts), such as Pompeo's North Korea trip and the South-North Korea summit, but we believe there is a need to once again review the issue since a new development has emerged," Cheong Wa Dae spokesman Kim Eui-kyeom told a daily press briefing.

The liaison office was earlier expected to be opened as early as this month. The proposed office comes under an agreement reached by South Korean President Moon Jae-in and North Korean leader Kim Jong-un when they first met in the border village of Panmunjom on April 27.

Moon and Kim are set to meet again next month in Pyongyang, which will mark their third bilateral summit since Moon took office in May 2017. The two held their second summit in Panmunjom on May 26.

The Cheong Wa Dae spokesman noted that the North too may wish to reconsider opening a joint liaison office with Seoul.

"This is not an issue that can solely be decided by our government and is one that needs to be discussed with the North side, but we have yet to learn how the North evaluates the change in conditions," Kim said.

He earlier said the third Moon-Kim summit will likely be held as scheduled.

The two Koreas have not yet set a specific date for the inter-Korean summit, only agreeing to hold the meeting in the North Korean capital in September. (Yonhap)