DiMaggio is known as an Iran specialist well-versed in the Obama administration's nuclear talks with the Middle Eastern nation. Thomas Pickering, former US envoy to the UN, and Robert Einhorn, US State Department's former special adviser for nonproliferation and arms control, were also among the American experts' group.

The diplomat was in Beijing and was returning to Pyongyang.

When asked what she discussed with Pickering, Choe answered, "I met with Pickering and I will discuss it when given the opportunity in the future."

This week's meeting took place amid a let-up in military tensions on the Korean Peninsula. The North did not conduct a nuclear test or a long-range rocket launch in April despite a view that it may take such a provocative act to mark a series of key political events in the month.

It was also held as South Koreans picked Moon Jae-in of the liberal Democratic Party as their new president. Expectations are running high over a change of mood in inter-Korean ties that have long been frosty.

When asked whether Pyongyang is preparing to hold dialogue with Seoul's Moon administration, Che replied, "We will observe the situation."

The US government has stated that it will not attach any special meaning to the so-called "track two" dialogue in Oslo.

"Track-two meetings are routinely held on a variety of topics around the world and occur independent of US government involvement," a State Department official said.

But North Korea watchers took note of the timing of the meeting this time, saying it may provide the two sides with a chance for a type of "exploratory" talks.

US President Donald Trump often talks tough about North Korea, emphasizing the need to put more pressure on the Kim Jong-un regime.

He recently said, however, he would meet Kim "under the right circumstances."

"If it would be appropriate for me to meet with him, I would absolutely, I would be honored to do it," Trump said in an interview with Bloomberg News earlier this month. (Yonhap)