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.

Since taking office in a snap election in June, the liberal Lee has taken steps to lower tensions with the nuclear-armed North, and the issue is one where he is expected to find common ground with Trump, who still boasts of his historic summits with North Korean leader Kim Jong Un.

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.