The United States has demanded North Korea ship some nuclear warheads, an intercontinental ballistic missile (ICBM) and other nuclear material overseas within six months, the Asahi newspaper said on Thursday, citing several sources familiar with North Korean issues.

US Secretary of State Mike Pompeo also appeared to have told North Korean leader Kim Jong Un, when they met earlier this month, that Washington might remove Pyongyang from a list of state sponsors of terrorism if the North ships out those nuclear items, the Asahi said.

If Pyongyang agrees to complete, verifiable and irreversible denuclearisation at a planned summit with the United States on June 12, Washington is considering giving guarantees for Kim's regime and including that stance in a joint statement by the two leaders, the newspaper report said.

North Korea has thrown into question next month's unprecedented summit between Kim Jong Un and US President Donald Trump, denouncing on Wednesday US-South Korean military exercises as a provocation and calling off high-level talks with Seoul.