North Korea is reportedly building a new tunnel at its nuclear test site.

38 North, a website which is dedicated to North Korea controlled by the U.S.-Korea Institute at Johns Hopkins University’s School of Advanced International Studies, said Wednesday a nuclear test doesn’t appear to be imminent but the new tunneling adds to North Korea’s ability to conduct more nuclear tests if it wants.

The site based its latest conclusions off on commercial satellite imagery of Punggye-ri, where North Korea has conducted three underground nuclear test explosions since 2006.

The appearance of a new tunnel makes it “more likely that they will conduct a test in the coming year,” Jeffrey Lewis, a nonproliferation expert at the Middlebury Institute of International Studies at Monterey, told The Washington Post.

Images taken between April and November show a new tunnel entrance, the fourth at the site, and signs of construction.

North Korea is believed to have a handful of nuclear bombs and to be pursuing nuclear-armed missiles that could hit the U.S. mainland. International talks aimed at ridding North Korea of its nuclear weapons were last held in late 2008. Its most recent test came in 2013.

North Korea has been urged to abandon its nuclear ambitions, it if it hopes to have any dialogue with South Korea. South Korea President Park Geun-hye said in November "there is no reason not to hold an inter-Korean summit if a breakthrough comes in solving the North Korean nuclear issue."

"It will be possible only when the North comes forward for a proactive and sincere dialogue. What counts most is North Korea's sincerity and determination to act on its words," she wrote in response to questions submitted by local and international news agencies in November.

The Associated Press contributed to this report.

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