Lee Hae-chan, the chairman of the DP, said that his party will dispatch a group of special envoys to explain the outcome of the Pyongyang summit to U.S. opinion leaders and listen to them.
The delegation is expected to visit the U.S. after President Moon Jae-in travels to New York next week for a meeting of the United Nations General Assembly.
"There are people who give a negative assessment to the summit. In particular, it is very important to grasp opinions in the U.S.," said Lee, who accompanied Moon on his recent trip to Pyongyang.
In a joint summit declaration, North Korean leader Kim Jong-un agreed to "permanently" dismantle a key missile testing site under the observation of international experts. He also expressed the country's readiness to close its nuclear complex in Yongbyon, depending on corresponding actions by Washington.
Lee said that North Korea's willingness to permanently shut down the Yongbyon complex signals the onset of an "irreversible" denuclearization process.
He vowed efforts to buttress the summit outcome at the legislative level, including parliamentary ratification of the April summit agreement.
Earlier this month, the government submitted a proposal for the ratification of the Kim-Moon summit declaration signed at the truce village of Panmunjom on April 27.
Source: Yonhap News Agency