"We are prepared for the long haul, but we approach this with clear eyes and with nerves of steel but with a clear goal in mind," she added.

South Korea is preparing to hold a summit with the North in late April. Last week, US President Donald Trump accepted an invitation from North Korean leader Kim Jong-un to a summit and proposed to hold talks before the end of May. 

This was the results of a visit of South Korean presidential envoys to Pyongyang earlier this month through which they met with the North Korean leader Kim. 

Kim expressed willingness to discuss denuclearization and promised to stop nuclear and missile tests until dialogue continues. This represented a significant turnaround from Pyongyang's repeated missile and nuclear provocations up until late last year. 

Kang was in Washington on a three-day trip to meet with US officials to discuss details on the upcoming back-to-back summits with the reclusive state.

The foreign minister attributed Pyongyang's changed attitude in part to sanctions and global solidarity to put pressure on the North and easing any of them would not happen until the North takes "significant" steps toward denuclearization. 

Asked if she trusts North Korea, which has a track record of agreeing to give up its nuclear weapons only to break its promises over and over again, Kang made clear that denuclearization is the way to go and the current situation seems to be much better than last year in dealing with the issue. 

"My president has been, from the very beginning, consistent and persistent in his message about North Korea. And that message has been that North Korea's missile and nuclear programs will never be accepted, but we want to engage to find a way toward a peaceful resolution," she said.

"This is a much better situation I think we all agree than we found ourselves mid-last year or even at the end of last year," she added. "We are cautiously optimistic that the talks will happen, and this will be a breakthrough for a peaceful resolution of the North Korean nuclear issue."

She emphasized the importance of talks and dialogue even with a regime that poses grave threat saying that there shouldn't be another war on the Korean Peninsula. 

"It is a regime that we still need to deal with. It poses grave security threat to Korea and to the whole world. You can only deal with this threat by engaging with it. We are absolutely clear that the military solution is not an option," Kang said.

"There cannot be another war on the Korean Peninsula. This requires a peaceful solution and to have a peaceful solution, you have to deal with them. You have to engage them," she noted.

The minister said that she has "confidence" in U.S. President Donald Trump's capability in dealing with the North Korean missile and nuclear issue going forward.

"I have confidence in his capability to deliver on his strong desire to come to grips with this issue of the North Korean missile and nuclear threats," she said. (Yonhap)