On April 2 2013, North Korea was one of three U.N. member states -- alongside Syria and Iran -- to vote against the organization's first treaty to regulate the global arms trade.
What other illicit trades is North Korea allegedly involved in?
North Korean citizens, including government officials have been involved in drug trafficking for years, according to the CIA World Factbook. It said in recent years North Korea had been linked to large shipments of heroin and methamphetamine.
Other illegal exports North Korea had intended for foreigners had come back to bite the country, Jang said. Counterfeit notes proved to be too poor a quality for foreign use but had ended up on the North Korean market. The problem was so widespread that Pyongyang would not accept widely counterfeit $100 notes for loyalty offerings, insisting $50 notes were paid instead, he said. For its part, the North Koreans have denied any involvement in counterfeiting.
Similarly, recreational drugs intended for international criminal markets had instead become a domestic headache, with many North Koreans now suffering from addiction to drugs such as meth and opium, he said. Click here to read New Focus' article on drugs in North Korea.
North Korea has denied involvement in illegal drugs and arms smuggling.
So how do ordinary North Koreans get by?
North Korea had traditionally fed its people but when the Soviet Union collapsed they had nothing and started bartering for food and all kinds of items, Jang said. Items were brought in from China to be traded so Chinese traders dominate the people's market.
New Focus International reported that black-market trading "provides the main source of income for most North Koreans." The black-markets were known as "jangmadang," it said.
Hoare said that when North Korea's economy had been stronger, workers had received money through the state's Public Distribution System. "Wages are worthless but now people trade on the markets."
He said markets were "tolerated" and could sometimes be seen down side streets. "My wife and I once walked through what was known as a 'frogs market'." The term arose because traders would "leap up and disappear like frogs and then reassemble behind you as it were."
What currency is used in North Korea?
The DPRK's official currency is the North Korean won, but Jang said everything in North Korea was pegged on the U.S. dollar, including the black market economy. The won was effectively "like toilet paper" he said and because all business was done using dollars the currency was used by people to barter even at the lowest levels of North Korean society.
Pyongyang had tried to revalue the currency but because everyone used U.S. dollars to trade, the dollar consistently went up and the won continued to fall in value, he said.
Hoare said euros were increasingly being used in some areas because North Koreans were worried the U.S. would somehow cut off dollars. Foreign currency flowed into North Korea in a number of ways including cross border trade with China and visiting foreigners, he said. All embassies also had to operate in foreign currency.
"We were not supposed to handle North Korean money. So it's pretty widespread. If you go into a hotel or restaurant prices are in foreign currency rather than Korean won," he said. North Koreans in Japan or South Korea and defectors were also reportedly sending money back -- usually through China, Hoare said.
In its article on jangmadang, New Focus International describes how money sent by a defector to his family in North Korea is laundered on the illegal markets.
What is the Kaesong Industrial Complex?
North Korea has said it will pull out all of its workers and suspend operations at the Kaesong Industrial Complex, accusing the South of seeking "to turn the zone into a hotbed of war."
The complex sits on the North's side of the border but houses the operations of several of South Korean companies. The complex is considered to be an important source of hard currency for Kim Jong Un's regime. More than 50,000 North Koreans work in the zone, producing hundreds of millions of dollars worth of goods each year. Those workers earn on average $134 a month, of which North Korean authorities take about 45% in various taxes.
South Korean company Hyandai Asan -- affiliated to the carmaker Hyundai -- was involved in the complex's development.
Hoare said the complex was "all that's left of the engagement policy all that was used from 1997 on." Jang said it was the last card of any significance held by North Korea as Pyongyang knew that outsiders saw it as a symbol of cooperation.
Are there any other such joint projects between the Koreas?
The only other joint business project had been the Mount Kumgang Tourist Region, Hoare said, Hyundai Asan operated tours.
However, tours were suspended when a North Korean guard shot dead a South Korean woman in 2008 and Pyongyang refused Seoul's request for an inquiry. "North Korea effectively confiscated the South Korean complex and began to use it themselves for tourism," Hoare said. "There was talk in 2007 of developing other such complexes but then there was a change of president."