North Korea calls hotline to South Korea in diplomatic breakthrough

North Korea and South Korea established contact on a hotline that's been dormant for almost two years Wednesday, a major diplomatic breakthrough following a year of escalating hostility and a move that could pave the way for future talks.

North Korea calls hotline to South Korea in diplomatic breakthrough

North Korean leader Kim Jong Un gave the order to open the line at 3:00 p.m local time (1:30 a.m. ET), according to an announcement on state media in the hours before the two phone calls to the South took place.

According to South Korea's Unification Ministry, the North Koreans made first contact at exactly the time ordered, and the sides were on the phone from 3:30 p.m. to 3:50 p.m. local time (South Korea is half an hour ahead of North Korea).

During the initial 20-minute connection, the two nations "checked technical issues of the communication line," according to a statement from South Korea's Unification Ministry.

The Unification Ministry said North Korea phoned for a second time several hours later on the Panmunjom hotline, suggesting the two sides wrap up business for the day."The North Korean side called our side at 6:07 p.m. (4.07 a.m. ET) and said 'let's call it a day today,'" the ministry confirmed.

Other than checking that the link-up was operational, it is unclear what was discussed. A ministry spokeswoman told CNN that there was no mention of future talks or the Olympics.A South Korean official communicates with a North Korean officer on the dedicated communications hotline at the border village of Panmunjom in Paju, South Korea, on Wednesday.

Contact had been initiated after Kim expressed hope that a North Korean delegation might participate in next month's Winter Games in Pyeongchang, South Korea.

The calls came just hours after an astonishing tweet from US President Donald Trump, who again taunted the North Korean leader, this time with a boast about the size of his nuclear button. During Kim's New Year's Day address, the North Korean leader had claimed he had a nuclear button of his own on the desk of his office.It's unlikely the timing of North Korea's offer of talks was related to Trump's tweet, however.

Relations between North and South Korea have warmed in recent days. During an unusually conciliatory New Year's speech, the North Korean leader extended a rare olive branch to the South, suggesting discussions about sending a North Korean team to the Winter Olympics should start "as soon as possible."In response, South Korean President Moon Jae-In called for swift measures during a Cabinet meeting Tuesday to smooth North Korea's participation in the Games.

Some analysts have said that North Korea's willingness to talk to South Korea could be an attempt to drive a wedge between the US and its South Korean ally.

"The South Korean government, being quite frightened about Washington's bellicosity, is quite ready to welcome the North Korean initiative, and this might lead to an annoyance in the US," said Andrei Lankov from Seoul's Kookmin University.

Others argue that talks between the Koreas could be advantageous for Washington. Tong Zhao, a fellow at the Carnegie-Tsinghua Center for Global Policy in Beijing, says all forms of communication should be welcomed.

"A better North-South relationship would help Washington and the international community to better understand North Korea and to talk it into taking substantive measures of self-restraint," he said.