South Korea urged the North on Wednesday to speed efforts for reunions of families separated since the war that divided the neighbors, but vowed to continue joint military drills with the United States, despite protests from Pyongyang.

Uncertainty remained whether the North would keep its pledge to hold the reunions ahead of the start of the drills, but the South said it would not use the military exercises as a means to secure the family event.

The North proposed the family reunions last week in a move welcomed by both China, its sole major ally, and the United States. If they come about, the reunions would be the first such event in more than three years.

But the North has yet to respond to a call by the South for the event to be held over six days in February and for a meeting to hammer out location and logistics.

"(We) expressed regret that the North has been showing an uncertain and passive position on the reunions of separated families, despite having accepted the proposal to hold them," a spokeswoman of South Korea's Unification Ministry said.

North Korean media have instead trumpeted the country's longstanding demand for a halt to the military drills, a frequent sticking point in the rivals' effort to improve ties.

The North calls the drills a prelude to war, despite the South's denial and assurance that they are defensive exercises that have been held for decades with no major incident.

Glyn Davies, the U.S. envoy on North Korea policy, met his South Korean counterpart in Seoul on Tuesday. Both rebuffed Pyongyang's call to stop upcoming military drills.

"We will continue on a transparent basis to conduct these defensive exercises so that we are ready should, God forbid, any contingency arise," Davies told reporters after the meeting.

Tensions soared last year as Pyongyang reacted angrily to tightened U.N. sanctions imposed in response to its latest nuclear test.

The two Koreas remain technically at war, as their 1950-53 civil conflict ended in a truce and not a peace treaty. The war left millions of families divided, with private travel across the border and communication, including phone calls, banned. (Reuters)