China’s highest-level visit to North Korea in nearly five years is set to get underway Thursday, as Pyongyang seeks to strengthen relations with both Beijing and Moscow amid growing coordination between its neighbors and the United States. Zhao Leji, China’s third-highest ranked official, will lead a delegation for a “goodwill visit” to the country to kickstart a “friendship year” marking 75 years of diplomatic ties, Beijing announced Tuesday. The three-day visit, at North Korea’s invitation,...