"The United States remains ready to engage North Korea in a constructive negotiation," a State Department spokesman said.

The spokesman said the United States was aware of the North Korean foreign ministry's demand regarding Pompeo but did not comment directly on it.

In a statement carried by state media, North Korean officials called Pompeo "reckless" and warned that future talks would be "lousy" if he returns to the table.

Pompeo, one of Trump's most trusted aides, was instrumental in encouraging him to walk away from a summit with North Korean leader Kim Jong Un in February in Hanoi.

Pompeo, who traveled four times to North Korea last year, has voiced hope for a deal with North Korea but has stood firm on full denuclearization before the United States eases sanctions.