NEW YORK (Kyodo) -- U.S. President Donald Trump on Friday nixed a planned trip to North Korea by Secretary of State Mike Pompeo, saying Pyongyang has not kept its promise to rid itself of nuclear weapons.
"I have asked Secretary of State Mike Pompeo not to go to North Korea, at this time, because I feel we are not making sufficient progress with respect to the denuclearization of the Korean Peninsula...," he said in a Twitter post.
The announcement came a day after the top U.S. diplomat said he would travel to North Korea next week in an effort to speed up negotiations on dismantling the country's nuclear weapons program.
North Korea has yet to take credible measures toward giving up its nuclear weapons and ballistic missiles despite its leader Kim Jong Un's commitment to "complete" denuclearization in a historic summit with U.S. President Donald Trump in Singapore in June.
Trump said he no longer believes China is "helping with the process of denuclearization" of North Korea as it once was, owing to Washington's tougher U.S. trade stance on Beijing.
He said Pompeo will visit North Korea at a later date, after Washington and Beijing settle an escalating trade dispute that has brought tit-for-tat exchanges of tariff hikes between the world's two largest economies.
"Secretary Pompeo looks forward to going to North Korea in the near future, most likely after our Trading relationship with China is resolved," Trump said in another Twitter post. "In the meantime I would like to send my warmest regards and respect to Chairman Kim. I look forward to seeing him soon!"
Kim is chairman of the country's Workers' Party of Korea.
Pompeo has told Japanese Foreign Minister Taro Kono on the phone he canceled his trip to North Korea, the Japanese Foreign Ministry said.
Pompeo originally planned to stop in Japan for talks with Kono and possibly with visiting South Korean Foreign Minister Kang Kyung Wha early next week after the trip, according to Japanese government sources.
Pyongyang's perceived reluctance to give up its nuclear weapons and ballistic missiles was underscored earlier this week, when a U.S. research group said the country appears to have halted dismantling work at a missile engine testing site in the country's northwest.
According to 38 North, a group that monitors North Korea, new imagery taken on Aug. 16 of the Sohae Satellite Launching Station in Tongchang-ri indicates "no significant dismantlement activity" has taken place at either the engine test stand or the launch pad since Aug. 3.
Speaking at a post-summit news conference in Singapore, Trump said Kim promised that Pyongyang would destroy a major missile engine testing site soon, in an apparent reference to Sohae.
The engine test stand at Sohae has been used to test large liquid-fueled rocket engines, applicable to both intercontinental ballistic missiles capable of hitting the United States and large space launch vehicles.