North Korea has lambasted South Korea's new defence chief for threatening to launch air strikes against the North and accused the South of causing "uncontrollable, extreme" tension on the peninsula.
The South's Defence Minister Kim Kwan-jin told a confirmation hearing on Friday that jets would bomb the North if it stages another attack like the shelling on a front-line island that killed four South Koreans.
Mr Kim took office on Saturday, replacing a predecessor who resigned amid criticism that South Korea's response to the November 23 shelling was too slow and weak.
The North's official Korean Central News Agency issued a statement on Sunday accusing the South of staging a series of "frantic provocations" including the defence minister's remarks.
"The frantic provocations ... are rapidly driving the situation on the Korean peninsula to an uncontrollable extreme phase," the official Korean Central News Agency said in a dispatch from Pyongyang.
The dispatch said South Korea plans to stage new naval drills with the United States soon, start its own live-fire drills from Monday and deploy missiles, rockets and other sophisticated weapons to Yeonpyeong Island that was hit by a North Korean artillery barrage.
"The puppet military warlike forces were reported to have already worked out the so-called 'retaliatory plan' which calls for sparking off an armed clash after getting on the nerves of the (North Korean) military and taking a large-scale counteraction under this pretext," it said.
South Korea's military declined on Sunday to confirm whether it has such a military retaliation. Joint Chiefs of Staff officers only said a new joint drill with the US - which would follow last's week's massive joint naval drill at Yellow Sea - is still under discussion with Washington and the live-fire exercise is a routine drill that has been scheduled well before the artillery barrage.