US - North Korea Relations: Why Is Kim Jong Un's Sister Speaking Out Instead Of The Supreme Leader?

Kim Jong Un’s sister Kim Yo Jong has attained new heights of prominence, recently delivering a stark warning against U.S. action in Asia. She’s played an increasingly important role in North Korean governance, especially when it comes to relations with Washington.

“If [the U.S.] wants to sleep in peace for the coming four years, it had better refrain from causing a stink at its first step," she told state news.

The quote appeared to be a response to the first Asia trip by U.S. Secretary of State Antony Blinken which is intended to shore up alliances with key allies in the region. Blinken met with leaders in both Tokyo and Seoul, rebuilding bridges that the Trump administration neglected.

Both North Korea and the Biden administration took the opportunity to try to set the tone for the coming years. While Biden officials told NBC News they wanted to soften rhetoric toward North Korea, a joint statement affirmed that complete denuclearization remains the end goal in the region.

“Recognizing that North Korea's arsenal poses a threat to international peace and stability, the ministers reaffirmed their commitment to the complete denuclearization of North Korea," the statement read.

As in the past, bringing up the prospect of denuclearization prompted a hostile response. What has changed is where the response is coming from, as Kim Yo Jong is hardly a household name in the U.S.

Her role as spokesperson for the authoritarian regime is less of a surprise to experts on North Korean politics. Kim’s prominence has increased in recent years, with Ha Tae-Keung, a South Korean official who sits on an intelligence committee, saying Kim Jong Un has ceded some of his previously undivided authority to her.

“The bottom line is that Kim Jong Un still holds absolute power but has turned over a bit more of his authority compared to the past,” Ha said, according to The Guardian. “Kim Yo Jong is the de facto second-in-command.”

When a three-week disappearance of Kim Jong Un in April 2019 prompted rumors the dictator was dead, many looked to his sister as a natural replacement. While Kim Jong Un resumed public appearances, his sister has continued to rise in prominence.