The SPA is the highest organ of state power under the North Korean Constitution, but it actually rubber-stamps decisions by the ruling Workers' Party of Korea.

"National Assembly Speaker Moon Hee-sang has already sent a letter about the proposal to hold an inter-Korean parliamentary meeting. We'll deliver the offer verbally, holding for such a meeting this year," Lee told pool reporters before the meeting.

At the start of the meeting, Lee expressed optimism about better inter-Korean ties as there is now, for the first time in a decade, a liberal administration that seeks engagement with North Korea.

"A good opportunity has come like today's as we came back to power. I've come here with stern resolve to make ever-lasting inter-Korean relations," Lee said.

Kim, 90, welcomed their visit, proposing that the two Koreas boldly move toward the common goal of achieving unification.

South Korea's presidential office Cheong Wa Dae earlier invited parliamentary leaders and the chiefs of five parties to Moon's trip to Pyongyang, which will conclude on Thursday.

But the parliamentary leadership rejected the offer, citing the schedule for the ongoing regular legislative session.

The main opposition Liberty Korea Party and the minor opposition Bareunmirae Party did not join the trip, saying that the timing is not proper amid slowing progress on North Korea's denuclearization.

The party chiefs were originally supposed to meet with An Tong-chun, a vice chairman of the SPA and two North Korean officials on Tuesday, but that meeting was canceled when, for undisclosed reasons, the South Koreans did not show up.

Critics said that the party heads might have expressed discomfort, as the planned gathering involved lower-ranking officials than Kim Yong-nam.

Lee rejected such speculation, saying that there was miscommunication in adjusting the meeting's schedule. (Joint Press Corps-Yonhap)