U.S. President Donald Trump has claimed that the headless body of North Korean leader Kim Jong-un's executed uncle was displayed to senior North Korean officials.

According to AFP news agency, which has seen excerpts from journalist Bob Woodward's upcoming book “Rage,” Trump said that Kim told him that he had his uncle's body displayed after ordering his execution in 2013.

Jang Song-thaek, the North Korean leader's uncle by marriage and a powerful figure within the regime, was purged for treason and corruption in 2013.

Trump told the Washington Post investigative journalist that Kim tells him everything and that he killed his uncle and put the body right on the steps, apparently referring to a building used by senior officials.

Also according to the book, Trump demanded North Korea give up five nuclear sites during his summit with Kim in Vietnam last year which ended without a deal.

The North Korean leader countered the demand saying Yongbyon is the biggest site, to which Trump retorted, "it's also the oldest."

According to excerpts, Kim did not offer further concessions.