* Delegation will aim to bring Pyongyang, Washington to talks
* Hopes for 'positive atmosphere' - S.Korean official
* Thawing relations cause hope for U.S.-N.Korea talks
* Washington insists Korean peninsula is denuclearised (Adds comments from delegation head, administration official; paragraphs 3,4,6,7)
By Christine Kim
SEOUL, March 5 (Reuters) - A South Korean delegation led by senior security officials will leave for North Korea on Monday, a presidential official said, aiming to bring together Pyongyang and Washington for talks on the North's nuclear programme.
The 10-member delegation, headed by National Security Office head Chung Eui-yong, will leave Seoul Air Base in Seongnam City near Seoul, the capital, at about 0500 GMT, the official said, on condition of anonymity.
"We will deliver President Moon Jae-in's wish to bring about denuclearisation of the Korean peninsula and permanent peace by extending the goodwill and better inter-Korean relations created by the Pyeongchang Winter Olympics," Chung said at the presidential Blue House.
The delegation hopes to speak with North Korean officials on starting dialogue between Pyongyang and the United States as well as other countries, he added.
The delegation includes National Intelligence Service chief Suh Hoon and Vice Unification Minister Chun Hae-sung.
Little has been disclosed of its agenda, but the delegation is expected to attend a dinner with North Korean officials on Monday, with another meeting set for early on Tuesday, said another administration official, who sought anonymity because of the sensitivity of the situation.
The government hopes the visit will create "a positive atmosphere", Unification Ministry spokesman Baik Tae-hyun told a regular briefing.
Thawing relations between the neighbours have prompted speculation of future direct talks between Washington and Pyongyang after months of tension and exchanges of insults between U.S. President Donald Trump and North Korean leader Kim Jong Un fuelled fears of war.
North Korea has not carried out any weapons tests since late November, when it tested its largest intercontinental ballistic missile. Inter-Korean talks began after Kim Jong Un said in his New Year's address that he wanted to engage the South.
Pyongyang has since sent athletes to participate in the Pyeongchang Winter Olympics in February, as well as a high-ranking delegation that included Kim's sister, Kim Yo Jong.
Both North Korea and the United States have expressed their willingness to talk to each other, but Washington demands Pyongyang "denuke" first. The North says it will not sit with the United States under preconditions.
Pyongyang has also fretted over a joint U.S.-South Korea military exercise, which it sees as practice for war, and which South Korean officials have said will start next month as planned, after being postponed for the Olympics and Paralympics.
Monday's delegation will leave on a special direct flight to Pyongyang rather than a jet chartered from a private airline.
The decision to use a special aircraft, most likely one of the private military jets used by President Moon Jae-in, according to administration sources, was unrelated to U.S. sanctions that bar entry for six months by vessels and aircraft that have visited North Korea.
The delegation's flight plans had already been negotiated with Washington regardless of the sanctions, the officials said.
Seoul had similar discussions with Washington this year when it sent South Korean athletes and journalists for a joint training session at the North's Masikryong ski resort ahead of the Olympics. The South Koreans took a chartered flight operated by Asiana Airlines Inc. (Reporting by Christine Kim; Additional reporting by Hyonhee Shin; Editing by Paul Tait and Clarence Fernandez)