China's President Xi Jinping, left, and South Korean President Park Geun-hye shake hands before a meeting Thursday, July 3, 2014, in Seoul, South Korea. The leaders agreed to work together to address North Korea's developing nuclear program.

Korean Peninsula a Dangerous Area for Diplomacy

China and South Korea united against North Korea's nuclear program Thursday, the same day Japan announced lowered sanctions against Pyongyang.

China's President Xi Jinping, left, and South Korean President Park Geun-hye shake hands before a meeting Thursday, July 3, 2014, in Seoul, South Korea. The leaders agreed to work together to address North Korea's developing nuclear program.

China's President Xi Jinping, left, and South Korean President Park Geun-hye shake hands before a meeting Thursday in Seoul, South Korea. The leaders agreed to work together to address North Korea's developing nuclear program.

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Thursday held good news and bad news for North Korea.

The good news for supreme leader Kim Jong Un’s North Korea is that Japanese Prime Minister Shinzo Abe announced that Japan would lift some of its sanctions against Pyongyang, according to Reuters.

The bad news for the country is that China and South Korea agreed to unite against North Korea's nuclear program, according to The Associated Press.

During a two-day trip to Seoul, South Korea, Chinese President Xi Jinping met with South Korean President Park Geun-hye to discuss North Korea’s nuclear missile testing. The two leaders reportedly agreed collaboration may be necessary in working toward a denuclearized Pyongyang, according to the BBC.

Pyongyang has performed three atomic tests since 2006, according to the AP. The BBC reports that the most recent test took place in 2013. All three incidents resulted in U.N. sanctions, according to the BBC.

[READ: South Korea Says Rival North Korea Fires 2 Short-Range Missiles Into Waters in Apparent Test]

North Korea tested a series of non-nuclear missiles this week ahead of the Chinese president’s arrival in South Korea. The country has vowed to continue its missile launches, despite international criticism.

"No matter how desperately the U.S. may find fault with [North Korea], it will continue to hold drills of launching high-precision tactical guided missiles, targeting the citadel of the gangsters," a North Korean military spokesman told Pyongyang news outlet KCNA, as reported by The Wall Street Journal.

China's leadership has typically visited Pyongyang before Seoul during trips to the Korean Peninsula, at least since Beijing and Seoul formed diplomatic ties in 1992, according to the AP and The Guardian.

President Xi's meeting in Seoul Thursday and subsequent condemnation of Pyongyang’s nuclear program has been described as a snub against North Korea.

“They will not feel good about this,” said Koh Yu-hwan, a North Korean studies professor at Seoul’s Dongguk University, according to the AP.

[ALSO: 2 Americans Held in North Korea]

China finds itself in a precarious position, as it is one of North Korea’s most important allies in terms of political and economic support, according to The New York Times. But Xi has not visited Pyongyang, nor has he invited Kim to Beijing, according to The Times.

Despite potentially wavering relations with China, North Korea managed to improve its ties with Japan this week after Japanese Prime Minister Abe announced lowered travel and economic sanctions between the two countries.

North Korean officials launched an “unprecedented” investigation into the abduction of 17 Japanese nationals kidnapped in the 1970s and 80s, Abe said, according to The Japan Times.

North Korea has definitively returned five of the abducted individuals to Japan, according to the Times. Pyongyang officials claim the rest are either dead or no longer in North Korea.

But officials said Tuesday that North Korea would form a 30-member team to investigate the issue further.

[MORE: Japan to Ease Sanctions in Return for Abduction Probe]

Abe apparently rewarded Pyongyang’s internal investigation by opening Japanese ports to North Korean ships traveling for humanitarian purposes. The Japanese Times speculates that this could open the door to Japan exporting goods like medical supplies to Pyongyang.

Tokyo has thus far honored the trade embargo imposed on North Korea through U.N. sanctions. The U.N. has also frozen Pyongyang’s assets abroad.

American relations with regional allies South Korea and Japan are being challenged by a politically active Beijing. Japan announced Tuesday it would reinterpret its pacifist constitution and increase its military activity, according to The New York Times.

“The growing pressure from China has changed the political debate within Japan,” said Kazuhisa Kawakami, a political expert at Meiji Gakuin University in Tokyo, according to The Times.

China and South Korea’s condemnation of North Korea this week conflict with Japan’s eased sanctions. Chun Yungwoo, the national security adviser to former South Korean President Lee Myung-bak, speculates China’s cooperation with South Korea could be a move to drive a wedge between Seoul, Japan and the U.S.

“Xi can’t afford to miss this opportunity to make bad relations between Japan and the Republic of Korea as bitter as possible,” he said, noting tension between Seoul and Tokyo that includes a heated dispute over the ownership of small islands in the waters between the two nations, according to The Wall Street Journal.