The parade featured the DPRK's largest ICBM, the Hwasong-17, KCNA reported.
"We will continue to take steps to strengthen and develop our nation's nuclear capabilities at the fastest pace," said DPRK leader Kim Jong Un during a speech late Monday, according to a transcript published by the official KCNA, Xinhua reported.
"The nuclear force of the Republic must be ready to exercise its responsible mission and unique deterrence anytime," Kim told the gathering, according to KCNA.
The fundamental mission of the country's nuclear force is to deter war, but that may not be the only use if other countries impose undesired circumstances, he added.