A senior North Korean official ridiculed American hopes for talks on Tuesday, as the U.S. and South Korea agreed to recalibrate their policy toward Pyongyang.
On Sunday, Washington called North Korean leader Kim Jong Un's recent speech about preparing for confrontation and diplomacy with the U.S. an "interesting signal."
The Biden administration is keen to hold talks with the North Koreans, and has said there need not be any preconditions.
But Kim Yo Jong, Kim Jong Un's sister warned state media Tuesday the U.S. was interpreting those signals in a way "which would plunge them into a greater disappointment."
Her comments come as top U.S. envoy to North Korea, Sung Kim, is set to meet with South Korean President Moon Jae-in.
Kim and South Korean counterpart Noh Kyu-duk agreed on Tuesday to reconsider a controversial working group coordinating policy on the North.
Established in 2018, the working group was intended to help the two allies work together on denuclearisation talks, humanitarian aid, sanctions enforcement and inter-Korean relations.
But it sparked controversy last year after the U.S. signalled its disapproval of a plan to reopen individual tourism between the North and South.
The U.S. ultimately concluded it had no place in approving South Korean decisions.
But a former aide to President Moon later told parliament the working group was increasingly seen as an obstacle to inter-Korean relations.