by Wang Chenxi, Lu Rui

SEOUL, Feb. 10 (Xinhua) -- All relevant parties should make joint efforts to broaden their dialogue channel so as to maintain peace on the Korean Peninsula, a South Korean expert said.

"Both sides on the peninsula have the good will to improve the inter-Korean relations. The key issue is other relevant parties can have dialogue with each other," Lee Sang-man, researcher at the Institute for Far Eastern Studies, Kyungnam University, said on Saturday.

South Korean President Moon Jae-in on Saturday met with Kim Yo Jong, the younger sister and special envoy of top leader of the Democratic People's Republic of Korea (DPRK) Kim Jong Un.

Kim Jong Un has invited Moon to visit Pyongyang, the presidential Blue House said. In response, Moon said, "Let's create conditions going forward and make it."

Moon has also dismissed a call by Japanese Prime Minister Shinzo Abe to quickly resume the U.S.-South Korea joint military exercises after the PyeongChang Winter Olympics.

Lee told Xinhua that all relevant parties should broaden their channel for dialogue and foster a peace agreement on the Korean Peninsula as soon as possible.

"The DPRK has taken a big step forward to send Kim Jong Un's sister as a special envoy who carried his letter and invited President Moon to visit Pyongyang, showing that Pyongyang cares about the peace on the peninsula," he said.

Moon's visit is highly possible, if South Korea and the United States downscale their military exercises, while DPRK agrees to freeze its nuclear program and stop testing missiles, he added.

"If they all step back at same time, then DPRK's 70th anniversary on Sept. 9, or the 11th anniversary of the Declaration for the Development of Inter-Korean Relations, Peace and Prosperity on Oct. 4, is good timing for the historic meeting," said the professor, who is optimistic about the third summit between the DPRK and South Korean leaders.

Late South Korean President Kim Dae-jung held the first inter-Korean summit in June 2000 with late DPRK leader Kim Jong Il, father of the current leader Kim Jong Un.

Late South Korean President Roh Moo-hyun met in Pyongyang with Kim Jong Il in October 2007.

He pointed out that the United States should be more open and active in having contact with the DPRK, especially when Pyongyang had shown willingness to improve the situation.

"It is very important for South Korea to coordinate with the United States to have dialogue with the DPRK," he added.

U.S. Vice President Mike Pence, who is also in South Korea to attend the opening ceremony of the PyeongChang Winter Olympics, on Friday visited wreckage of the Cheonan warship destroyed in an incident in March 2010. South Korea said the warship was sunken by torpedoes fired by the DPRK, a charge repeatedly denied by Pyongyang.

Local media reported that there is no interaction between Pence and the DPRK delegation at a welcome reception hosted by Moon on Friday.

Lee said the current goal for South Korea is not the unification of the Korean Peninsula, but the prevention of war. The priority for the two Koreas is holding meetings between their militaries to eliminate the risk of armed conflict.

"The process of unification could be as long as several decades and we couldn't achieve that in a short time. But realizing peace on the Korean Peninsula is the first step forward," he added.