North Korea said it would reopen a long-closed border hotline with South Korea on Wednesday to discuss attending the Winter Olympics, hours after US President Donald Trump appeared to mock the Norths leader by saying he has a "bigger and more powerful" nuclear button than Kim Jong Un. The Norths unscheduled statement came a day after Seoul proposed high-level discussions amid a tense stand-off over North Koreas missile and nuclear programs. That followed Kims New Years address, in which he said he was open to speaking with Seoul and would consider sending a delegation to the Winter Olympics to be held just across the border in Pyeongchang next month. US officials said Washington would not take any talks between North and South Korea seriously if they did not contribute to denuclearizing North Korea. A State Department spokeswoman said North Korea "might be trying to drive a wedge of some sort". Kim gave an order to reopen a border hotline with South Korea at the truce village of Panmunjom at 0630 GMT on Wednesday, said North Korean official Ri Son Gwon. That gesture came only hours after Trump again ridiculed the North Korean leader. "Will someone from his depleted and food starved regime please inform him that I too have a Nuclear Button, but it is a much bigger & more powerful one than his, and my Button works!" Trump tweeted. While appearing to open the door to discussing taking part in the Winter Olympics - which would be the first direct negotiations in more than two years - Kim also sternly warned that he would push ahead with "mass producing" nuclear warheads in defiance of UN sanctions. His New Years Day speech came after a steep increase in missile launches in 2017, as well as the Norths sixth and most powerful nuclear test. Kim, who has vowed to develop a nuclear-tipped missile capable of reaching the United States, said he had a "nuclear button" on his table. The hotline, located in the truce village of Panmunjom, remained operational until February 2016, with operators from both countries checking it twice a day. The channel was shut down when relations deteriorated over a dispute involving the Kaesong industrial complex, which was jointly operated by both countries.