SEOUL, Oct. 6 (Yonhap) -- South Korean political parties on Saturday expressed the expectation that U.S. Secretary of State Mike Pompeo's upcoming trip to North Korea would yield substantive progress in Pyongyang's denuclearization.

Pompeo is set to visit Pyongyang on Sunday to meet with North Korean leader Kim Jong-un to discuss steps toward the communist state's nuclear disarmament and work out details of a second summit between U.S. President Donald Trump and Kim.

"Tomorrow, Secretary Pompeo is set to visit the North, and chances are high that a plan for considerable progress (in denuclearization) will be made, should the second North Korea-U.S. summit materialize," Kang Byung-won, the spokesman for the ruling Democratic Party, said in his commentary.

Kang reiterated his party's stance that the National Assembly should back up ongoing peace talks by ratifying the April summit declaration between South Korean President Moon Jae-in and Kim that included their resolve to pursue the "complete" denuclearization of the peninsula.

The spokesman, in particular, pressured the main opposition Liberty Korea Party (LKP) to support his party's push for the parliamentary ratification.

"It is wrong for the LKP to remain a peace obstructionist," he said.

The LKP for its part stressed that there should be practical discussions on the North's tangible denuclearization steps.

"During Secretary Pompeo's visit to the North, they should discuss the 20 to 60 nuclear weapons the North possesses, a full declaration of its nuclear materials and facilities, inspections and verification," he said.

"We welcome the resumption of the North-U.S. talks, and we hope that based on the talks, there will quickly be another summit between the two sides, and we anticipate that there will be great progress in efforts toward the North's denuclearization, reform and openness," he added.

The minor Party for Democracy and Peace sought to rein in growing expectations for Pompeo's visit.

"We need to watch it in a cool, measured manner," Kim Jeong-hyeon, the party's spokesman, said.

The Justice Party voiced hope that Pompeo will return with the "fruits of peace."

Pompeo's fourth trip comes after the North Korean ruler's reaffirmation of his denuclearization resolve during his third summit with Moon in Pyongyang last month.

The North has committed to taking additional denuclearization steps, such as shutting down its long-range missile engine test site and launching pad in Dongchang-ri on the west coast in the presence of international inspectors and closing its main Yongbyon nuclear complex should the U.S. take "corresponding measures."

Source: Yonhap News Agency