North Korea as tensions mount over Pyongyang’s weapons ambitions.Moon, who was sworn in last week, warned the North’s nuclear and rocket programmes were "advancing rapidly", days after Pyongyang launched what appeared to be its longest-range missile yet.
"I will never tolerate the North’s provocations and nuclear threats," he said on a visit to the defence ministry, urging the South’s military to adopt a "watertight defence posture".
"We are living in the reality where there is a high possibility of military festivities" along the disputed sea border off the Koreas’ west coast or along the heavily fortified land frontier that divides them, Moon said.
The president made his remarks after his country’s unification ministry suggested talks with the North should resume.
"Our most basic stance is that communication lines between South and North Korea should open," said Lee Duk-haeng, a front man for the ministry. "The unification ministry has considered options on this internally but nothing has been decided yet."