The RoK had been expected to brief the Security Council some time this week on an international investigation into the sinking of the corvette Cheonan on March 26 that killed 46 sailors. Seoul has accused the DPRK of torpedoing the ship.

The DPRK asked Mexico's Claude Heller, the Security Council's rotating president, for a separate briefing session, Yonhap News quoted an unidentified diplomatic source in New York as saying.

The mounting antagonism between the two Koreas has unnerved investors, worried about armed conflict breaking out in the region, and set off a diplomatic scramble on all sides to cool tensions.

Many analysts say neither side is ready to go to war, but see the possibility of more skirmishes in a disputed sea border off the west coast or along the heavily armed border between the two Koreas.

Pyongyang has denied involvement in the Cheonan's sinking, saying accusations against it were part of a US-led conspiracy and threatening war if Seoul imposes sanctions.

Reuters