BEIJING - The Republic of Korea (ROK) has threatened to hit back with air strikes against the Democratic People's Republic of Korea (DPRK) and "punish the attacker thoroughly" should Pyongyang launch another assault, ROK Defense Minister-designate Kim Kwan-jin warned on Friday.
The tough words came as the largest ever United States-Japan military exercises kicked off in waters off the Korean Peninsula, and as the United Nations' atomic watchdog voiced "great concern" about Pyongyang's nuclear ambitions.
Analysts said further conflicts are highly likely to be sparked should the military drills continue, and military threats should be replaced by negotiations.
The US joined forces with Japan in a giant display of military firepower dubbed "Keen Sword", with 60 warships, 400 aircraft and 45,000 troops.
The maneuvers in the East China Sea dwarfed US-ROK exercises this week in the Yellow Sea.
The Pacific allies are for the first time being joined by ROK military observers.
Japan sent soldiers in an observer capacity to take part in joint US-ROK military exercises in July, held after the sinking of the Cheonan, a 1,200-ton ROK naval vessel.
In Seoul, Defense Minister-designate Kim told a parliamentary confirmation hearing that if Pyongyang attacks again, "we would definitely use the air force to strike back".
Kim said the ROK would exercise its right to self-defense and "punish the attacker thoroughly until the source of hostility is eliminated".
Seoul also plans five days of artillery firing next week, but held off on scheduling a drill on Yeonpyeong - which was hit in the Nov 23 attack and is just 12 km from the DPRK's coast - saying it could come "by the end of this year at the latest".
China has called for negotiations with Pyongyang, saying that talking is better than "brandishing weapons".
Washington, Tokyo and Seoul have so far remained cool regarding Beijing's proposal for the Six-Party Talks that would also involve Moscow - opting instead for their own three-way meeting to be hosted by US Secretary of State Hillary Clinton on Monday.
"We'll keep a close watch on this meeting," said Chinese Foreign Ministry spokeswoman Jiang Yu on Thursday, warning against any moves that would "heighten tensions and intensify confrontation".
Clinton said earlier she was discussing with Chinese and Russian officials "how we can work together to try to avoid conflict".
International Atomic Energy Agency Director-General Yukiya Amano in Vienna expressed "great concern" over reports that the DPRK had built a modern new uranium enrichment plant.
Analysts called for talks instead of military exercises, and said the DPRK now needs to be pacified instead of being further irritated.
AFP and Wang Di contributed to this story.