North Korea on Thursday lashed out at US Secretary of State John Kerry for what it claimed to be his attempt to undermine the dignity of its leadership, while also accusing him of driving the US-North Korea relationship to the worst possible state.

"The rubbish made by bete noire Kerry against the dignity of the supreme leadership of the DPRK is nothing but a shriek made by the wretched one bound for ruin after sustaining only bitter defeat and shame in the stand-off with the DPRK, failing to realize the wild ambition for 'bringing down' the DPRK," an unidentified spokesman for the North's foreign ministry was quoted as saying.

DPRK stands for the North's official name, the Democratic People's Republic of Korea.

The remarks came two days after the US state secretary, while speaking at the ongoing World Economic Forum in Davos, insisted the US missile defense system set to be deployed in South Korea -- the Terminal High-Altitude Area Defense or THAAD -- was to "cope with the nuclear weapons of North Korea" and its reckless and unverified impulsive dictator Kim Jong-un.

In an interview with the North's state-run Korean Central News Agency, the North Korean foreign ministry spokesperson insisted his country has already become a nuclear power and that Kerry's remarks only represented the "extreme horror and uneasiness" felt by the United States.

"He had better repent of his crime of having pushed the DPRK-US relations and the regional situation into the worst catastrophe through the extreme hostile policy toward the DPRK during his tenure of office," the North Korean official was reported as saying.

"Whoever provokes even a little the dignity of the supreme leadership of the DPRK, which represents our destiny, will be made to pay a very high price beyond imagination." (Yonhap)