WASHINGTON (Yonhap News) -- U.S. Secretary of State John Kerry and his South Korean counterpart, Yun Byung-se, will focus on ways to denuclearize North Korea when they meet next week in Washington, the State Department said Friday.

"We do still believe the onus is on North Korea," the department's deputy spokeswoman, Marie Harf, said at a press briefing.

She pointed out North Korea has committed on multiple occasions to denuclearize.

"It is a key topic of discussions with the South Koreans that will be next week, but there are a host of other issues that we work on together as well," Harf said.

The South Korean foreign minister plans to visit Washington next week for talks with Kerry and some other top U.S. officials.

It would be the first meeting between Yun and Kerry since North Korea executed Jang Song-thaek, leader Kim Jong-un's once-influential uncle, in December. Yun and Kerry are scheduled to meet on Tuesday.

Harf also reiterated calls for North Korea to refrain from taking provocative action.

"I don't want to prejudge or guess about what might happen or what they might do in the next few months, but it's clear to say that we are encouraging them not to take those kinds of actions," she said.

There have been growing worries that the communist regime will turn to a provocative mode in a bid to solidify internal unity following the purging of Jang.