Chinese President Xi Jinping (right) and South Korean President Park Geun-hye greet children waving the two countries' national flags at the presidential Blue House in Seoul on Thursday. Xi has yet to visit North Korea. Kim Hong-ji/Reuters/Landov hide caption

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A propaganda painting is seen outside the People's Palace of Culture in Pyongyang, North Korea, in 2011. North Korean state media reported Friday that the nation has detained a U.S. tourist. Feng Li/Getty Images hide caption

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North Korea apparently doesn't like either of them: President Obama and South Korean President Park Geun-hye at a news conference in Seoul, South Korea, on Friday. Carolyn Kaster/AP hide caption

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This image was taken Jan. 30 by astronauts aboard the International Space Station. North Korea is the large dark patch in the middle. The only significant light is from its capital, Pyongyang. The next photo adds reference points. NASA.gov hide caption

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South Korean Park Yang-gon (left) and his North Korean brother Park Yang Soo get emotional as they meet Thursday during the Separated Family Reunion Meeting at Diamond Mountain resort in North Korea. Park Hae-soo/AP hide caption

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