South Korea says it will continue high-level talks with North Korea with "clear eyes" amid global warnings that Pyongyang might be playing for time to continue its nuclear-arms programme.
"We have to make the most" of the opportunity, South Korean Foreign Minister Kang Kyung-wha told the BBC.
The two Koreas earlier agreed to march under a "unified Korea" flag at next month's Winter Olympics in the South.
The talks come as the US and its allies vowed to keep pressure on the North.
On Wednesday US Secretary of State Rex Tillerson said sanctions were "really starting to hurt", expressing confidence that the pressure would eventually force the North to the negotiating table over its nuclear and ballistic missile programmes.
Last year, US President Donald Trump said that America would destroy North Korea if forced to defend itself or its allies.
Also on Wednesday, Japanese Foreign Minister Taro Kono said the world should not be blinded by Pyongyang's recent "charm offensive".
"It is not the time to ease pressure or to reward North Korea," Mr Kono said, Reuters news agency reported. "The fact that North Korea is engaging in dialogue could be interpreted as proof that the sanctions are working."
Ms Kang told the BBC: "I think we understand North Korea better than anybody, having dealt with North Korea for decades, having had series of discussions off and on.
"We haven't had any significant engagement in the recent past - but this is an opportunity.