The US military also deployed other nuclear-capable weapons, including B-52 bombers and submarine USS Cheyenne during its joint drills with South Korea.

South Korea claims the joint military drills are defensive in nature, but the DPRK denounced them as rehearsals for a northward invasion.

The committee warned of an "unimaginable holocaust and disaster" and a crisis in inter-Korean ties if "the rehearsal for a nuclear invasion into the DPRK" carries on this year.

South Korea's Defense Ministry on Thursday and Friday rejected the calls from the DPRK, saying the annual joint military drills between Seoul and Washington will be conducted as scheduled.

"If North Korea (the DPRK) makes military provocations citing our normal military exercises, our military will sternly and ruthlessly retaliate against such provocations," Defense Ministry spokesman Kim Min-seok said at a press briefing.

The United States on Thursday dismissed the proposals from the DPRK, saying its "core policy" on the country remains unchanged.

Washington and its allies, Japan and South Korea, have set Pyongyang's moves to abandon its nuclear weapons and existing nuclear program as a condition for resuming the six-party talks, a mechanism also involving Russia and China.

"We'll continue to hold North Korea (the DPRK) to these commitments and its international obligations," State Department spokeswoman Jennifer Psaki said, adding "we won't accept North Korea as a nuclear-armed state."

"The ball remains in their court and they haven't taken any steps to change the views of the international community on this issue," she said.

China on Thursday asked all parties to show restraint on the nuclear issue of the Korean Peninsula.

Chinese Foreign Ministry spokesman Hong Lei said safeguarding peace and stability on the Korean Peninsula is the duty of all sides and is in line with their common interests.

Noting that China has always advocated solving the nuclear issue through dialogue, Hong said the overall situation on the peninsula is fragile and China expects all sides to avoid provocative moves and help stabilize the situation.