* Leaders of two sides to meet at 0030 GMT Friday

* First summit between the two in more than a decade

* Kim, Moon to plant symbolic tree at border (Adds quotes from South; North's delegates; paragraphs 4-10)

By Christine Kim and Josh Smith

SEOUL, April 26 (Reuters) - South Korean President Moon Jae-in will greet North Korean leader Kim Jong Un on Friday as the latter crosses a military demarcation line to enter the South for the first summit between the two sides in more than a decade, South Korea said.

South Korean honour guards will then escort the leaders to a welcome ceremony at a plaza in Panmunjom, the border village where the summit is to be held, the South's presidential chief of staff, Im Jong-seok, told a media briefing.

Official dialogue between Kim and Moon will begin at 10:30 a.m. (0130 GMT) at the Peace House in Panmunjom, an hour after Kim is scheduled the cross the border at 9:30 a.m. (0030 GMT).

"This summit will focus more on denuclearisation and securing of permanent peace than anything else," Im said on Thursday.

"I feel North Korea is sending their key military officials to the summit as they too, believe denuclearisation and peace are important."

Kim will be accompanied by nine officials, among them his sister, Kim Yo Jong, who led the North's delegation to the Winter Olympics in South Korea in February and Kim Yong Nam, the North's nominal head of state.

In addition, there will be Kim Yong Chol, a former intelligence chief and Choe Hwi, the chairman of a sports panel. The North sent athletes to the Winter Olympics, where the neighbours also fielded a joint women's ice hockey team.

Kim Yong Chol was previously chief of the Reconnaissance General Bureau, a North Korean military intelligence agency South Korea has blamed for the deadly 2010 sinking of the Cheonan, a South Korean navy corvette.

Also in the delegation are Ri Su Yong, a member of the North's politburo and Ri Myong Su, the chief of the general staff of the Korean People's Army.

Ministers on the trip include defence minister Pak Yong Sik, and foreign minister Ri Yong Ho, besides an official spearheading peaceful reunification efforts, Ri Son Gwon.

South Korea's delegation is comprised of seven officials, including the ministers for defence, foreign affairs and unification.

After the end of the first session of talks, Kim Jong Un and Moon will have lunch separately before holding a tree-planting ceremony in the afternoon, Im said.

A pine tree will be planted on the demarcation line to symbolise "peace and prosperity", Im said, using soil from Mount Paektu in North Korea and Mount Halla in South Korea.

Kim and Moon will water the tree with water brought from the Taedong River in the North and the Han River in the South, Im said. Afterwards, Moon and Kim will take a walk together in Panmunjom before beginning the next round of talks.

At the end of the talks, Kim and Moon will sign a pact and make an announcement, Im said. Later, they will have dinner on the South's side and watch a video clip themed 'Spring of One', he added. (Reporting by Christine Kim and Josh Smith Editing by Clarence Fernandez)

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