North Korea has about 110 pounds of weapons-grade plutonium, which is enough to make 10 nuclear weapons, the South Korean defense ministry said Wednesday. The reclusive East Asian country threatened Sunday it was going to test-launch an intercontinental ballistic missile (ICBM).

The North’s stockpile of plutonium increased substantially in 2016, compared to 88 pounds it had in 2014, according to the defense white paper released Wednesday, Yonhap News Agency reported. It further noted that Pyongyang has a “considerable” ability to manufacture weapons based on highly-enriched uranium.

Last August, North Korea confirmed it had restarted the production of plutonium in the country, following speculations it reopened its Yongbyon nuclear facility that month. The Yongbyon reactor was shut down in July 2007.

The South Korean defense white paper reportedly stated the Kim Jong Un-led nation increased the number of troops to 1.28 million in 2016 from 1.2 million in 2014. During the same period, the air force declined from 120,000 to 110,000 soldiers while the country’s navy remained unchanged at 60,000 troops.

On Sunday, North Korea’s foreign ministry said the country developed the ICBM to fortify its self-defense capabilities to counter “the ever more undisguised nuclear war threat from the U.S.,” according to the North’s official Korean Central News Agency.

The ministry also said the country developed a hydrogen bomb and “had access to standardized nuclear warheads by bolstering up its nuclear weapons on a high level at an unimaginably high speed on the strength of self-development” despite the international sanctions.

“The ICBM will be launched anytime and anywhere determined by the supreme headquarters of the DPRK [Democratic People’s Republic of Korea],” the ministry added.