South and North Korea on Thursday closed contact via a reopened cross-border hotline without reaching an agreement as the North did not comment on Seoul's latest offer for high-level talks, officials said.

Both sides are seeking to hold talks to discuss the North's potential participation in the PyeongChang Winter Olympics. To this end, North Korea reopened the suspended communication channel at the shared border village of Panmunjom Wednesday after nearly two years.

The move followed North Korean leader Kim Jong-un's diplomatic overture to the South on New Year's Day. He expressed a willingness to send a delegation to the games, which will be held in South Korea next month.

The resumption of the line came quickly after Seoul on Tuesday proposed discussions about Olympic cooperation and ways to improve long-stalled ties between the two countries.

But both sides ended contact on the second day, hours before closing time, as North Korea called it a day without mentioning Seoul's offer for dialogue, according to Seoul's unification ministry.

The revival of the dialogue channel indicates a first step toward efforts to improve ties, which have been marred by North Korea's nuclear and missile threats.

Seoul hopes that better inter-Korean relations could help pave the way for the resolution of the North Korean nuclear issue and for broader talks between the US and North Korea.

Ri Son-gwon, the head of North Korea's state agency in charge of inter-Korean affairs, said Wednesday that the channel's opening was an order from Kim. He added that North Korea will consult with the South about the Olympics in a sincere manner.

But the official did not specify whether Pyongyang would accept the format of high-level talks proposed by Seoul.

The North could want working-level sports talks instead of a high-level meeting or may attach strings to having talks, such as Seoul and Washington's suspension of their joint military drills.

Some experts said that the North's olive branch to Seoul is aimed at weakening international sanctions and driving a wedge in the decades-long alliance between the South and the US

In contrast to his peace offensive to Seoul, the North's ruler warned the US that a "nuclear button" is placed on his desk and that the whole US mainland is within the range of his country's missiles.

"We will calmly wait for the North's reply and review the next steps," said an official at the Ministry of Unification who is handling inter-Korean affairs.

The two sides are expected to negotiate details about talks, including agenda items, if their contact through the hotline goes smoothly.

The ministry official said that if Ri were be the North's chief negotiator, his South Korean counterpart would be Unification Minister Cho Myoung-gyon.

He said that the government will form a delegation after taking into account the agenda and format of talks. (Yonhap)