North Korean leader Kim Jong Un has provoked further controversy after stating his country possesses miniaturized nuclear warheads which can be used on ballistic missiles.
The leader has requested his military be ready for possible attacks against the United States and South Korea, especially after the United Nations imposed harsh sanctions on the country over its nuclear tests.
US and South Korea have already started military drills which North Korea called "nuclear war moves."
"The nuclear warheads have been standardised to be fit for ballistic missiles by miniaturizing them," the North Korea's state Korean Central News Agency quoted Kim as saying as he inspected the work of nuclear scientists, adding "this can be called a true nuclear deterrent."
"He stressed the importance of building ever more powerful, precision and miniaturised nuclear weapons and their delivery means," the KCNA said.
Kim also inspected a thermo-nuclear warhead, KCNA said, referring to a miniaturized hydrogen bomb - a device the country said it tested on Jan. 6.
North Korean newspaper Rodong Sinmun published photos of Kim along with scientists standing next to an object which looks like a model of a nuclear warhead.
They also showed a large object similar to the KN-08 intercontinental ballistic missile (ICBM) previously put on display at military parades, with Kim holding a half-smoked cigarette in one of the images.
Reacting to the images, South Korea’s Defence Ministry expressed its disbelief in the claimed miniaturised nuclear warhead as well as the deployment of an ICBM.
South Korean and US officials doubt North Korea has developed the technology to create such weapons.
North Korea conducted its fourth nuclear test on Jan. 6, claiming to have set off a miniaturised hydrogen bomb - a claim disputed by many experts and the governments of South Korea and the United States. The blast detected from the test was simply too small to back up the claim, experts said at the time.
The country also launched a long-range rocket in February, provoking an international reaction as well as additional sanctions from South Korea.
North Korea has been "effective in evading sanctions" by continuing to engage in banned trade, "facilitated by the low level of implementation of Security Council resolutions by Member States," a UN Panel of Experts has said.
"The reasons are diverse, but include lack of political will, inadequate enabling legislation, lack of understanding of the resolutions and low prioritization," it said.