The United States and South Korea on Friday postponed a joint naval drill scheduled for next week, citing the need for more preparation on the part of the US forces.
Deputy Defence Minister Chang Kwang Il made the announcement on the sidelines of an Asian security conference in Singapore, South Korea's KBS radio said. A Defence Ministry spokesman in Seoul said the drills have been rescheduled to take place in two or three weeks.
The manoeuvres had been announced at short notice about one month ahead of their original schedule as a show of military strength following the March 26 sinking of a South Korean warship blamed on a North Korean submarine torpedo.
Forty-six sailors died in the sinking of the corvette Cheonan near the disputed maritime border between the two Koreas in the Yellow Sea.
North Korea, on Friday, called for a new investigation into the incident by the UN Security Council and warned of the "toughest retaliation" if the council discussed punitive sanctions against Pyongyang, the Yonhap news agency quoted a statement by the North's Korean Central News Agency as saying.