After weeks of hurling threats at the United States and its allies, North Korea announced plans on Tuesday to restart a reactor at its main nuclear complex that it had agreed to shut down more than five years ago.
The declaration demonstrates Kim Jong Un's commitment to the country's nuclear weapons program that the international community has persistently but unsuccessfully tried to get it to abandon.
The North's state-run Korean Central News Agency (KCNA) reported that the reclusive state's atomic energy department intends to "readjust and restart all the nuclear facilities" at the Yongbyon nuclear complex.
Those facilities include a uranium enrichment facility and a reactor that was "mothballed and disabled" under an agreement reached during talks between North Korea, the United States and four other nations in October 2007, KCNA said.
"It's yet another escalation in this ongoing crisis," said Ramesh Thakur, director of the Center for Nuclear Nonproliferation and Disarmament at Australian National University in Canberra.
The high tensions on the Korean Peninsula have resulted in Pyongyang severing a key military hotline with Seoul and declaring the armistice that stopped the Korean War in the 1953 to be void.
At the same time, the United States has carried out a number of displays of its military strength amid annual training exercises, flying nuclear-capable B-2 stealth bombers, massive Cold War-era B-52s and F-22 Raptor stealth fighters over South Korea.
And on Monday, South Korea warned that any provocative moves from North Korea would trigger a strong response "without any political considerations."
The real motivation behind the North's announcement Tuesday on the nuclear facilities remains unclear, Thakur said, suggesting that it was unlikely to make a big difference militarily for the country, which is already believed to have between 4 and 10 nuclear weapons.
They may be hoping to use it as a bargaining chip in future talks, he said, or it could be an attempt by the country's young leader, Kim Jong Un, to shore up support domestically.
"It's just a very murky situation," Thakur said. "The danger is that we can misread one another and end up with a conflict that no one wants."
China, a key North Korean ally, expressed regret over Pyongyang's announcement about the reactor.
"China has consistently advocated denuclearization on the peninsula and maintaining peace and stability in the region," Chinese Foreign Ministry Spokesman Hong Lei said at a regular news briefing Tuesday.
Japanese Chief Cabinet Secretary Yoshihide Suga, meanwhile, said the move would need to be dealt with in a serious manner, noting that it breached the North's previous commitments.
A torrent of threats
The North's latest declaration comes after it has delivered a steady stream of verbal attacks against South Korea and the United States in recent weeks, including the threat of a nuclear strike.
Pyongyang's angry words appear to have been fueled by recent joint military exercises by the United States and South Korea in the region, as well as tougher U.N. sanctions in response to the latest North Korean nuclear test in February.
Much of the bellicose rhetoric, analysts say, isn't matched by the country's military capabilities.
Still, the U.S. Navy was moving a warship and a sea-based radar platform closer to the North Korean coast in order to monitor that country's military moves, including possible new missile launches, a Defense Department official said Monday.
The North's announcement Tuesday follows a new strategic line "on simultaneously pushing forward economic construction and the building of the nuclear armed force" that was set out at a meeting of a key committee of the ruling Workers' Party of Korea headed by Kim Jong Un on Sunday.
The work of adapting and restarting the nuclear facilities "will be put into practice without delay," KCNA said.
The measures would help solve "the acute shortage of electricity," as well as improving the "quality and quantity" of the country's nuclear arsenal, it said.
In June 2008, the usually secretive North Korean government made a public show of dramatically destroying the cooling tower of the Yongbyon reactor to demonstrate its compliance with a deal to disable its nuclear facilities.
But only two months later, as its leader at the time, Kim Jong Il, balked at U.S. demands for close inspections of its nuclear facilities, the North started to express second thoughts.
It said it was suspending the disabling of its nuclear facilities and considering steps to restore the facilities at Yongbyon "to their original state."
In November 2009, it announced it was reprocessing nuclear fuel rods as part of measures to resume activities at Yongbyon. It noted success in turning the plutonium it had extracted into weapons-grade material.