On Monday, the U.S. envoy said Washington hoped to receive a positive response from the DPRK on a proposal for negotiations. But he also said the U.S. would continue to impose tough sanctions. Kim Yo Jong, the sister of the DPRK's top leader, responded on Tuesday, saying the U.S. had unrealistic expectations that could only result in disappointment. DPRK leader Kim Jong Un said recently that the country must be ready for both dialogue and confrontation.