North Korea has begun producing weapons grade plutonium, according to satellite images from a United States research institute.
The Washington Post reports that a small nuclear reactor, the Yongbon nuclear facility, has been restarted after being mothballed for the past six years. Images taken August 31 show plumes of white steam coming up from the reactor, a sign that the electrical system for the weapons facility is coming back online.
Due to the secretive, insular nature of the North Korean government vis-à-vis international inspection, there's no way to confirm the nuclear capabilities of the reactor. Furthermore, North Korea's uranium-enrichment program is even more shrouded in mystery, due to the fact that testing for it takes place in underground or covered facilities less susceptible to satellite surveillance.
If the Yongbon reactor is fully functional, it has the capability to produce 13 pounds of plutonium per year; enough for one or two nuclear bombs. Experts believe that North Korea currently has enough plutonium for four to eight bombs of a size equal to the ones the United States dropped on Hiroshima and Nagasaki at the end of World War II.
North Korea is one of nine countries with nuclear weapons. Five of those countries are signatories of the Nuclear Non-Proliferation Treaty (NPT) signed into law in 1970, and include (in chronological order): the United States, Russia, the United Kingdom, France, and China.
The Democratic People's Republic of North Korea, along with Israel, Pakistan, and India, are non-signatories to the treaty; of the four, North Korea is largely seen as the most antagonistic to American foreign policy and international interests, and is a source of consternation for East Asian neighboring states as well. In pressing for a military strike on Syria, the United States has tried to persuade Chinese support by noting the chemical weapon capabilities of North Korea, according to Fox News.