Pompeo asked top North Korean official Kim Yong-chol about the regime's secret nuclear facilities and warheads and asked whether North Korea has been increasing production of enriched uranium, Yomiuri reported, citing multiple sources in Washington, Seoul and Tokyo.
Pompeo also said he heard information about the North expanding a missile factory in the northern city of Hamheung and said it's not good for U.S.-North Korea relations.
Kim denied expanding and said the construction at the missile factory is only preparing the facility for heavy rains, according to the report.
At the meeting June 6 and 7 in Pyongyang, Pompeo pressured the North to take action to implement denuclearization pledges and Kim said the North is willing to do so, but without a detailed timeline. Instead, Pyongyang requested an announcement of the formal end to the Korean War.
Friday, the Diplomat revealed the location of the North's secret uranium enrichment site, known as Kangson. The report claimed the site matches a covert nuclear facility monitored by U.S. intelligence for years.
The site appears to be located in a Pyongyang suburb with easy access to an expressway near the capital. Satellite images taken in recent years show frequent visits by trucks and vehicles believed to have transported materials for uranium enrichment.
In May, the Washington-based Institute for Science and International Security issued a report on an unknown nuclear centrifuge site with a similar name, Kangsong.