North Korea said on Wednesday it sees no more need to negotiate with the United States, accusing Washington of plotting to "bring down" its regime, and threatened to strike back using all its military resources.
North Korea routinely seeks to raise tensions ahead of annual joint military drills by U.S. and South Korean forces that usually begin in March. This year, Pyongyang has offered to suspend nuclear testing if Washington calls off the exercises.
However, North Korea's National Defence Commission said on Wednesday the United States was inching close to "igniting a war of aggression" and that the Obama administration was working to trigger its collapse.
The commission, Pyongyang's supreme leadership body, is headed by North Korean leader Kim Jong Un.
"Since the gangster-like U.S. imperialists are blaring that they will "bring down" the DPRK ... the army and people of the DPRK cannot but officially notify the Obama administration of the USA that the DPRK has neither need nor willingness to sit at the negotiating table with the U.S. any longer," it said.
Using the North's official name of the Democratic People's Republic of Korea (DPRK), it said Pyongyang had decided "to write the last page of ... U.S. history".
"(Smaller), precision and diversified nuclear striking means and ground, naval, underwater, air and cyber warfare means will be used," the commission said in the statement carried by the official KCNA news agency.
U.S. President Barack Obama said in an interview carried on YouTube on Jan. 22 the Internet would inevitably penetrate even a country as reclusive and closed as North Korea and bring about change. "Over time you will see a regime like this collapse," Obama said.
The angry response by North Korea's defense commission came after its foreign ministry said on Sunday Washington had rejected its invitation for the top U.S. nuclear envoy handling North Korea to visit for talks.
Sung Kim, the U.S. special representative for North Korea policy, said in Beijing he was open for talks with the North Koreans. However, the State Department denied there was any plan for talks or change in its position that Pyongyang must first show it was serious about ending its nuclear ambitions.