THE United States and South Korea rattled their sabres at Pyongyang yesterday, announcing a new joint military plan against the North.

US Defence Secretary Ashton Carter and his South Korean counterpart Han Min Koo voiced “grave concern” at North Korea’s nuclear weapons and missile programmes.

At a press conference after closed-door meetings, the Mr Han said his country would not tolerate further military provocations by Pyongyang.

Mr Carter called North Korea an “up-close, dangerous and continuing threat.”

He and Mr Han demanded that Pyongyang not only cancel its nuclear weapons programme but also close down its reactor at Yongbyon.

However, neither of them announced any new steps towards returning full control of the South’s armed forces to the Seoul government.

Under current arrangements, a US four-star officer would take operational control of South Korean troops in the event of a war with the North.

In 2006, then defence secretary Donald Rumsfeld suggested that South Korea could be granted full control of its forces as early as 2009.

Seoul insisted that more time was needed and a transition date of 2012 was agreed.

That timetable was further postponed on the pretext of increased tension with the Pyongyang, including two nuclear weapon tests in 2009 and 2013 and the alleged sinking of the South Korean corvette Chenoan by a North Korean torpedo.

Last year, Washington and Seoul agreed to postpone the transfer indefinitely, saying it would happen on a “conditions-based” timetable that included improvements to South Korean military capabilities.