North Korea on Monday confirmed the purge of Jang Song Thaek, the uncle of dictator Kim Jong Un and second-most-influential figure in the regime. A meeting of top officials of the ruling Workers' Party on Sunday decided to expel Mr. Jang from the party and strip him of all titles for antistate crimes, according to a report from North Korea's official Korean Central News Agency. The removal of Mr. Jang marks the highest-level purge in the North Korean regime since Mr. Kim came to power at the end of 2011 following the death of his father, Kim Jong Il.