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.