Yuri Kadobnov/AFP/Getty Images

After his February summit with President Trump ended early and without a deal, North Korean leader Kim Jong Un launched an internal government purge, executing five top officials, South Korea's Chosun Ilbo newspaper reports.

He blamed the Hanoi summit's collapse on Kim Hyok Chol, special envoy to the United States, and four other foreign ministry officials who carried out working-level negotiations, a person with knowledge of the matter told Chosun Ilbo. The officials were all accused of spying for the United States, and executed by a firing squad in March.

The newspaper also reports Kim's top aide, Kim Yong Chol, is being forced to do hard labor, and other officials have been sent to internment camps for political prisoners.