South Korea is government , on Tuesday ( 04/22/2014 ) , said the activity in the center of North Korea’s nuclear test increased ahead of a visit by U.S. President Barack Obama .
South Korean military ” is currently detecting some activity around the nuclear test Punggye - ri ” , said a spokesman for South Korea’s defense ministry .
North Korea is planning to hold a ” surprise nuclear test or just pretending to hold a nuclear test , ” he said .
The trials were recently conducted in February of 2013 - has sparked a severe tensions for months on the Korean peninsula .
North Korea has conducted a nuclear test three times in the past . This trial was also conducted in 2006 and 2009 . All these trials resulted in the imposition of UN sanctions against Pyongyang .
On Monday ( 04/21/2014 ) South Korean Joint Chief of Staff to form a special task force to monitor the situation .
Multinational talks aimed at ending North Korea’s nuclear ambitions have been stalled for years .
Late last month , North Korea threatened a ” new form ” of this nuclear test . It is not known what the purpose of the ” new form ” is.
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Although Pyongyang has conducted tests on a number of nuclear devices , but it is believed they have not been able to launch a missile .