The North's main Rodong Sinmun newspaper claimed that the U.S. is modernizing its nuclear arsenal under its "aggression strategies," but made no mention of the missed year-end deadline for the country to declare all its nuclear programs under an international agreement.
"Our republic will continue to harden its war deterrent further in response to the U.S. stepping up its nuclear war moves," the paper said in a commentary, carried by the country's official Korean Central News Agency.
North Korea often uses "deterrent," "war deterrent," or "nuclear deterrent" to refer to its nuclear weapons.
The U.S. has repeatedly stressed that it has no intention of attacking or invading North Korea, and would normalize relations with the North if it gives up nuclear programs.
Pyongyang has promised to abandon its nuclear ambitions in return for energy aid and political concessions. In October, it pledged to disable its nuclear facilities and issue a declaration on its atomic programs by the end of the year in return for the equivalent of 1 million tons of oil from its partners in the six-way talks - the U.S., China, Japan, South Korea and Russia.
The North missed the deadline, and has not explained why.
Pyongyang shut down its only functioning reactor in July, and began disabling it and other facilities under the watch of U.S. experts in November. That process was slowed by technical difficulties but continues.
U.S. nuclear envoy Christopher Hill plans to discuss the stalemate next week during visits to Japan, South Korea, China and Russia.
Also Friday, another North Korean newspaper, Minju Joson, said the country had no option but to slow the disablement work because the U.S. and other negotiating counterparts delayed fulfilling their commitments to the communist nation.
A North Korean official made a similar claim last week.
"This shows that it is fully up to the U.S. and related countries whether the goal of denuclearizing the Korean peninsula would be attained or not," the paper said in a commentary, also carried by KCNA.
The commentary did not mention the nuclear declaration.
In Seoul, South Korean President-elect Lee Myung-bak met a group of U.S. experts on Korea, including former U.S. Defense Secretary William Perry and former Deputy Defense Secretary Paul Wolfowitz, seeking their advice and views on the future of nuclear talks with the North.