North Korea said it will strengthen self-defensive nuclear weapons capability in a decision adopted at a congress of its ruling Workers' Party congress, its KCNA news agency reported on Monday, in defiance of U.N. resolutions, Reuters reported.
Isolated North Korea has come under tightening international pressure over its nuclear weapons program, including tougher U.N. sanctions adopted in March backed by lone major ally China, following its most recent nuclear test in January.
The decision formalizes a position previously held by North Korea, which declared itself "a responsible nuclear weapons state" and disavowed the use of nuclear weapons unless its sovereignty is first infringed by others with nuclear arms.
"We will consistently take hold on the strategic line of simultaneously pushing forward the economic construction and the building of nuclear force and boost self-defensive nuclear force both in quality and quantity as long as the imperialists persist in their nuclear threat and arbitrary practices," KCNA said of the congress decision.
The two Koreas remain in a technical state of war since their 1950-53 conflict ended in a truce, not a peace treaty. North Korea regularly threatens the South and its major ally, the United States, which it accuses of planning a nuclear attack.
The congress is the first to be held in 36 years amid anticipation by the South Korean government and experts that leader Kim Jong Un will use it to further consolidate power. Kim became leader in 2011 after his father's sudden death.
Since the latest round of U.N. resolutions, North Korea has continued to engage in nuclear and missile development, and claimed that it had succeeded in miniaturizing a nuclear warhead and launching a submarine-based ballistic missile.