North Korea said Monday it would bolster its nuclear capabilities "both in quality and quantity" to counter the newly-disclosed nuclear war plan of the United States.

North Koreans realize how wise their communist regime has been in beefing up nuclear deterrence against Washington's growing threats, the North's official Korean Central News Agency (KCNA) said in a commentary.

It cited a recent disclosure by former CIA Director and Defense Secretary Leon Panetta. He said in his memoirs published earlier this month that the U.S. reserved the option of a nuclear strike on North Korea in case of a war.

"This is yet more evidence of grave nuclear threats against the Democratic People's Republic of Korea," the KCNA said, using the nation's official name.

It added that the North's nuclear arsenal is a "precious sword of justice" to protect its people from the U.S.' threats and a "reliable shield" to defend peace in Northeast Asia.

"Our armed forces and people will further bolster nuclear deterrence in quality and quantity until the complete termination of the U.S. hostile policy and its nuclear threats," said the KCNA.

The secretive North conducted three known underground nuclear tests in 2006, 2009 and 2012. 

Many observers agree on the likelihood of another nuclear detonation. (Yonhap)