High-ranking North Korean party and military official Choe Ryong Hae, second left, prepares to depart for China as a special envoy of North Korean leader Kim Jong Un, at Pyongyang airport, North Korea Wednesday, May 22, 2013. The trip by Choe, a vice marshal who is director of the General Political Bureau of the Korean People's Army, is the highest-profile visit by a North Korean official to neighboring China this year and takes place at as Beijing is under pressure to rein in Pyongyang's provocations. AP Photo/ Kim Kwang Hyon High-ranking North Korean party and military official Choe Ryong Hae, center left, shakes hands with Chinese Ambassador Liu Hongcai as Choe departs for China as a special envoy of North Korean leader Kim Jong Un, at Pyongyang airport, North Korea Wednesday, May 22, 2013. High-ranking North Korean party and military official Choe Ryong Hae, front right, shakes hands with officials as he departs for China as a special envoy of North Korean leader Kim Jong Un, at Pyongyang airport, North Korea Wednesday, May 22, 2013. Choe Ryong Hae, director of the General Political Bureau of the Korean People's Army (KPA), center, and other delegates from left, Kim Hyong Jun, deputy minister Foreign Affairs, Ri Yong Gil, Col. Gen. of KPA, Kim Song Nam, vice department director of the Central Committee of the Workers party of Korea, and Kim Su Gil, Lt. Gen. of KPA, pose before leaving Pyongyang Airport for China, North Korea Wednesday, May 22, 2013. North Korean leader Kim Jong Un dispatched a high-profile official and close confidant to travel to China on Wednesday as a special envoy while Beijing is under pressure to rein in its belligerent neighbor. FILE - In this July 18, 2012 file photo, North Korea's Vice-Marshal Choe Ryong Hae, director of the General Political Bureau of the Korean People's Army, speaks during a meeting at the April 25 House of Culture announcing North Korean leader Kim Jong Un's new title of marshal, in Pyongyang, North Korea. Choe, a "special envoy" for North Korean leader Kim Jong Un left Pyongyang on Wednesday, May 22, 2013, for China, the North's only major political and economic benefactor. AP Photo/Jon Chol Jin, File PYONGYANG, North Korea (AP) - North Korean leader Kim Jong Un dispatched a high-profile official and close confidant to China on Wednesday as Beijing faces pressure to rein in its belligerent neighbor. Choe Ryong Hae, a top Workers' Party official and a vice marshal tasked with supervising the North Korean military, departed on a chartered Air Koryo flight with a political and military delegation. Chinese Ambassador Liu Hongcai was among the dignitaries on the tarmac for his departure. Choe, dressed in his military uniform, arrived later in Beijing and left the airport in a motorcade. He was meeting with Wang Jiarui, head of the Communist Party's international affairs office and long a point man for China on contacts with North Korea, according to China's official Xinhua News Agency. The trip is the highest-profile visit by a North Korean official to China this year, and it takes place as the new leadership in China shows frustration with North Korea and a greater willingness to work with Washington to harry Pyongyang over its nuclear weapons programs. China is Pyongyang's economic and diplomatic lifeline, providing nearly all of its fuel and most of its trade, and foreign analysts said the trip could be an attempt to win more aid and repair ties. There are signs of strains in relations between Beijing and Pyongyang over North Korea's nuclear efforts, which included an underground nuclear test in February. That test, the country's third, was followed by U.N. sanctions and a protracted period of high tensions as North Korea threatened nuclear strikes on Washington and Seoul. The Chinese ambassador's sendoff to the North Korean delegation made up of top party and military officials was cordial. He chatted with Choe briefly, commenting on the weather as they shook hands before the vice marshal boarded his plane. The rhetoric from Pyongyang has fallen off in recent weeks, and there have been tentative signs of diplomacy in the region as envoys from the U.S., Japan, South Korea, China and Russia have consulted on how to engage with the North Koreans. Separately, the Japanese government said Wednesday that it was looking into re-opening official talks with North Korea to resolve questions over the abductions of Japanese citizens decades ago. The announcement by Chief Cabinet spokesman Yoshihide Suga raised worries among allies who fear Tokyo's focus on that issue might weaken diplomatic efforts on Pyongyang's nuclear weapons program. Japanese Prime Minister Shinzo Abe had indicated he would potentially be open to holding a summit with Kim Jong Un if it would lead to a breakthrough on the abductions issue. Abe dispatched a senior adviser to Pyongyang last week, catching Seoul and Washington off guard. In recent months, the relationship between Beijing and Pyongyang appeared strained. In one sign, China's state-run Bank of China said this month it had notified the Foreign Trade Bank of North Korea that its accounts were closed and all financial transactions suspended. In another, Chinese fishermen said gunmen in North Korean military uniforms held a crew captive at gunpoint for two weeks before finally releasing the boat this week. The ship's owner said the captain was beaten and the vessel's fuel stolen. Choe's trip is believed to be the first top-level meeting between North Korean and China since Chinese Politburo member Li Jianguo went to Pyongyang in late November bearing a letter from Xi Jinping, who had just been installed as China's party chief. Choe may be tasked with trying to improve relations between Pyongyang and Beijing in his meetings with Chinese officials, said Koh Yu-hwan, a North Korea expert at Dongguk University in Seoul, South Korea. "This is an indirect way for the countries to hold a summit meant to restore ties," Koh said. The visit comes amid discussions about a possible trip by South Korean President Park Geun-hye to China next month. Choe and his delegation may ask for more economic aid from Beijing and try to explain North Korea's recent military moves, including short-range projectile launches off the east coast, said Lee Ji-sue, a North Korea specialist and professor at Myongji University in Seoul, South Korea. Leader Kim Jong Un hasn't visited Beijing since he took power from his father, Kim Jong Il, who visited China in August 2011 just months before his death that December. China is North Korea's top trade partner. According to the most recent figures from Korea Trade-Investment Promotion Agency in Seoul, which collects North Korean trade data, China accounted for 89 percent of North Korea's exports and imports in 2011. The 2012 figure was not available. The numbers show deepening economic ties between North Korea and China in the last few years as the North's economic exchange with South Korea weakened. In 2005, China accounted for 53 percent of North Korea's annual trade, according to KOTRA. China and North Korea are jointly developing a pair of special economic zones: Rason on the Korean Peninsula's northern tip and Hwanggumphyong, an island in the Yalu River that marks their border to the southwest. Choe, a close Kim family friend, often is pictured standing next to the leader, along with Jang Song Thaek, the uncle who visited China in August last year. Choe holds a slew of top posts, including director of the General Political Bureau of the Korean People's Army, member of the Presidium of the powerful Political Bureau of the ruling Workers' Party, vice chairman of the Central Military Commission of the Workers' Party, and member of the Supreme Assembly. Also Wednesday, the North revealed that Kim Jong Un had named a hardline general, Kim Kyok Sik, as his new army chief. There were no other details from Pyongyang. Kim Kyok Sik previously led the Korean People's Army until 2009. He also was defense minister, a separate position considered lower-ranking than army chief, until being recently replaced by a little-known general, Jang Jong Nam. Kim is the former commander of battalions believed responsible for attacks in 2010 that killed 50 South Koreans. Associated Press writers Kim Kwang Hyon in Pyongyang; Sam Kim, Youkyung Lee and Hyung-jin Kim in Seoul, South Korea, and Eric Talmadge in Tokyo contributed to this report.