North Korean leader Kim Jong-un has boasted of a surge of strength and hailed the elimination of "factional filth" following the execution of his uncle last month.
Kim used his New Year message to highlight North Korea's "resolute" action to bolster the country's unity "by 100 times".
During the speech, which was broadcast on state television, he said: "Our party took resolute action to remove ... scum elements within the party last year."
He accused his uncle Jang Song-thaek, who was previously considered the second most powerful man in the secretive state, of committing treason.
The North Korean leader said, "Our party's timely, accurate decision to purge the anti-party, anti-revolutionary elements helped greatly cement solidarity within our party".
State news agency KCNA said Jang was executed after being tried for "such hideous crime as attempting to overthrow the state by all sorts of intrigues and despicable methods with a wild ambition to grab the supreme power of our party and state".
His death was announced on December 13.