US condemns 'reckless' North Korean leader

U.S. Secretary of State John Kerry has described North Korean leader Kim Jong Un as "reckless" and "insecure" after the execution of his powerful uncle, according to an ABC News interview.

The execution of Jan Song Thaek, who was considered the second most powerful man in the secretive country, showed why the world must make a united stand against North Korea's nuclear weapons program, Mr Kerry said in the interview taped for Sunday broadcast on ABC's "This Week" program.

Mr Kerry said the nature of "this ruthless, horrendous dictatorship" and Kim's insecurities raised the stakes for China, Russia, Japan, South Korea and the United States to "stay on the same page" and push ahead on denuclearization.

"To have a nuclear weapon potentially in the hands of somebody like Kim Jong Un just becomes even more unacceptable," Kerry told ABC.