Kerry: US will not submit to 'irrational or reckless provocation' by North Korea

Yun said North Korea dominated the conversation. The country recently conducted its third nuclear test in violation of United Nations resolutions and has since increased its bellicose rhetoric, including declaring invalid the armistice that ended the Korean war in 1953.

“We agreed to further strengthen credible and robust deterrence vis-a-vis North Korea's nuclear and conventional provocations,” he said. 

The Obama administration has sent advanced bombers and destroyers to the region in a show of strength. The tensions will be a key part of Obama's talks with South Korean President Park Geun-Hye when she visits the White House next month.

Kerry did extend an olive branch, however.

“We make it clear – as we have consistently – that the United States believes there is a very simple way for North Korea to rejoin the community of nations and make it clear that they want to pursue a peaceful path” and denuclearize, Kerry said. The U.S. has “made it clear we are prepared to help them” with taking care of their impoverished people “if they are ready to bring their behavior in line with the United Nations and global community requirements.”

Kerry went on to say that the U.S. and South Korea are making progress on a civilian nuclear agreement that is a key plank of Park's agenda for U.S.-Korean relations. She wants the Obama administration to revise the 1974 agreement that bans South Korea from enriching uranium and allow the country to reprocess spent atomic fuel. 

“We have a long record of close cooperation on this issue,” Kerry said, “and we are committed to finding a workable, expeditious way forward.”

He also said that climate change and clean energy development would be important topics during his visit next week.