South Korea said Wednesday the North has made "considerable" progress in nuclear capabilities recently, citing the increased amount of its fissile material and improved warhead miniaturization technology, according to Yonhap.

In its 2016 defense white paper, the Ministry of National Defense estimated that North Korea has some 50 kilograms of weapons-grade plutonium, sufficient to manufacture 10 nuclear weapons.

In 2014, the biennial report estimated the North's stockpile of plutonium at about 40 kilograms.

The ministry also said the North made significant advancements in its ability to miniaturize nuclear warheads and enrich uranium without providing details.

The white paper comes amid fresh tensions over North Korea's threat to launch an intercontinental ballistic missile that could reach the US mainland.

Source: MENA