South Korea's President said that there are signs that North Korea is preparing for a fifth nuclear bomb test amid reports of increased activity at the country's main nuclear test site.
In a regular meeting with her top adviser, President Park Geun Hye said that North Korea could carry out such a test to try to bolster morale as the country deals with tough international sanctions imposed after it conducted a fourth nuclear test and a long-range rocket launch earlier this year.
Park didn't elaborate on what signs pointed to another nuclear test, but ordered the military to be ready to deal with any provocation by Pyongyang.
Speculation about a fifth nuclear test increased last month when the North's state media cited leader Kim Jong Un as ordering a test of a nuclear warhead and ballistic missiles capable of carrying warheads. Kim's order came amid rising animosity with South Korea and the United States over their annual military drills that North Korea describes as an invasion rehearsal.
Analysts say an atomic test could happen before North Korea holds a landmark ruling Workers' Party congress in early May so that Kim can burnish his image as a powerful leader at home and further cement his grip on power.The drills are set to run until next week.
South Korea's Yonhap news agency said that South Korean and US authorities detected two to three times more vehicle and personnel activities than normal this month at the northeast Punggye-ri nuclear test site - where all four bomb tests took place.