Guess who wants to grab headlines again? Kim Jong-un has reopened the plutonium factory at Yongbyon again, according to State Department officials who spoke to Reuters, further defying the UN. Pyongyang has long threatened to restart its operations at the shuttered facility, and it now appears that they have made good on those threats:

North Korea has restarted production of plutonium fuel, a senior U.S. State Department official said on Tuesday, showing that it plans to pursue its nuclear weapons program in defiance of international sanctions.

The U.S. assessment came a day after the U.N. nuclear watchdog said it had “indications” that Pyongyang has reactivated a plant to recover plutonium from spent reactor fuel at Yongbyon, its main nuclear complex.

The latest developments suggest North Korea’s reclusive regime is working to ensure a steady supply of materials for its drive to build warheads, despite tightened international sanctions after its fourth nuclear test in January.

The Kim regime has not limited itself to nuclear expansion, either. The Washington Post’s Anna Fifield reports that North Korea has engaged in a broad buildup that has analysts worried about Kim’s plans:

But even as Kim Jong Un’s regime presses ahead with its nuclear program, it is investing considerable resources in upgrading its conventional facilities, according to satellite imagery.

“Lots of people say that if they have a nuclear deterrent, they won’t need conventional weapons,” said Curtis Melvin, a researcher at the U.S.-Korea Institute at Johns Hopkins University who has an encyclopedic knowledge of North Korea’s geography. “But under the Kim Jong Un era, there has been a big increase in spending on the economic and conventional military side.” …

Using satellite images, Melvin has spotted significant construction work at the October 3 shipyard near Wonsan, a port city on North Korea’s east coast, with land being extended and a bridge being built between a Korean People’s Army naval base and the shipyard. It appeared that the bridge will carry a new railway line, he said.

The South Korean government said today that it’s “seriously worried” about the sudden shift back to Yongbyon and in the buildup of conventional forces:

They should be “seriously worried,” and not just because of the buildup. The response from the UN and from the multilateral talks in the Pacific Rim have done little to stop the Kim regime from nuclear and missile tests. The main limitation on Pyongyang has been its economy, which it claims to also have improved over the last year, but that’s likely a smokescreen. In the past, these episodes of saber-rattling preceded demands for fuel oil and food, essentials that the Kim regime could not provide for its nation. With the younger Kim in place, that may still be the game plan — or he might have something more dangerous in mind. Either way, it seems unlikely that South Korea and Japan will get much assistance from the Obama administration or China, except to back a new round of UN sanctions that has long passed the point of diminishing returns.