SEOUL, May 29 (Xinhua) -- If top leader of the Democratic People's Republic of Korea (DPRK) Kim Jong Un and U.S. President Donald Trump can sit down for talks, the fact itself would become a great change of history, South Korea's ruling party chief said Tuesday.

Choo Mi-ae, chairwoman of the Democratic Party, said at a press conference with foreign correspondents in Seoul that if Kim and Trump sit over the same table, the fact itself will mean a great historical change.

Trump abruptly cancelled his meeting with the DPRK leader, originally scheduled for June 12 in Singapore, last week, but the DPRK said it was ready to talk at any time with the U.S. side.

South Korean President Moon Jae-in met Saturday with the DPRK leader in the border village of Panmunjom for a surprise second meeting with Kim, just a month after their holding the third-ever inter-Korean summit on April 27.

Moon said Sunday that both Kim and Trump were willing to hold a first-ever DPRK-U.S. summit as scheduled. The South Korean president met in Washington with Trump last week to discuss the DPRK-U.S. summit.

"North Korea (DPRK)-U.S. summit is not a matter of possibility, but a must-have," said the Democratic Party chair. "Peace and denuclearization on the Korean Peninsula is not just a matter of one country, but of the entire world."

Choo said the DPRK-U.S. summit must be held as peace-loving people all around the world wished peace settlement on the peninsula.

Though the Kim-Trump summit was to be held as scheduled, Choo said, there remained a possibility for all issues not to be resolved at a time. She noted that one step cannot resolve everything at once.

Choo emphasized the importance of obligations that bind the concerned parties to implement a possible agreement, which can be reached at the DPRK-U.S. summit.

Citing U.S. Secretary of State Mike Pompeo, Choo said the U.S. side mentioned the complete, verifiable, irreversible peace regime (CVIP) in return for the complete, verifiable, irreversible denuclearization (CVID), which Pompeo said can be ratified by the U.S. Senate if the DPRK-U.S. summit successfully ends.

She said President Trump also promised to guarantee the DPRK's regime security if the DPRK leader determines the denuclearization, noting that the U.S. Senate ratification will mean no change in the possible DPRK-U.S. agreement regardless of political situations.

After the April 27 summit, Moon and Kim signed the Panmunjom Declaration, agreeing on the complete denuclearization and the turn of the current armistice agreement into a peace treaty by the end of this year. The peninsula remains technically at war as the 1950-1953 Korean War ended with an armistice.

The National Assembly of South Korea failed to pass the resolution to support the Panmunjom Declaration through the unicameral parliament as the main conservative opposition Liberty Korea Party objected to it.

"The Panmunjom Declaration refers to preventing a nuclear war and building a peace regime (on the peninsula). It is an unimaginably valuable thing that cannot be valued in terms of money," said Choo.

Choo urged politicians to make bipartisan efforts to pass the Panmunjom Declaration resolution as there remained a long way to go toward achieving the eventual goal of permanent peace and denuclearization.?