North Korea now has enough material to make 10 nuclear warheads, according to the latest military analysis by its southern neighbor.

The conclusion is based on Pyongyang’s estimated 50-kg stockpile of weapons-grade plutonium, and the reckoning that each warhead would require an average of 4 to 6 kg of nuclear material.

Citing Seoul’s 2016 Defense White Paper, released Wednesday, the Korea Times reports that the North’s plutonium stash has jumped from 40 to 50 kg over the past two years. These new supplies of nuclear material originate from Pyongyang’s reprocessing of its spent fuel rods, the report says.

An unnamed Defense Ministry official told the Times that its conclusion came after South Korea and the U.S. “analyzed various aspects such as the operation situation of the North’s nuclear reactor.”

The ministry also suggests that Pyongyang is developing both intercontinental ballistic missiles (ICBM) and submarine-launched ballistic missiles, although the same defense official told the Times that the North’s ICBM capabilities have “yet to reach a reliable level.”

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The report comes just days after North Korean leader Kim Jong Un said the country was “in the final stages of test-launching” ICBMs, which attracted a stern warning from the Pentagon.

With less than nine days to go until the next U.S. President assumes office, there are concerns that the incoming Administration either has no solid plans to respond to Pyongyang’s advances in nuclear weaponry, or that it might inadvertently escalate the Korean Peninsula’s already contentious security situation.

In addition, Seoul also noted the further expansion of the North’s conventional armed forces in the white paper, reports the Korea Times. According to the white paper, the total number of North Korean soldiers rose from 1.2 million to 1.28 million, and a unit engaging in cyberwarfare has expanded from 6,000 members to 6,800.

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