North Korean leader Kim Jong Un ’s powerful sister yet again taunted South Korean efforts to improve ties, state media reported Wednesday, saying that her country will never accept Seoul as a diplomatic partner.

North Korea ruled out a role for South Korea in any regional diplomatic talks related to Pyongyang and warned of “countermeasures” against “the most hostile state” as it criticized the ongoing military cooperation between Seoul and Washington.

North Korea is stepping up criticism of South Korea's new President Lee Jae Myung as he prepares for his first summit with U.S President Donald Trump, calling Lee's efforts to engage with Pyongyang a "pipedream".