The arrest put the number of Americans held in North Korea at four, as Washington and Pyongyang remain at loggerheads over the North's nuclear and missile ambitions.
The new unit, the CIA said, will work closely with the United States intelligence community to monitor the North Korean threat.
If the dispute between the U.S. and North Korea escalated into military action, it would adversely impact New Zealand exporters.
The Chinese expert also expressed his opinion on the possible consequences of a new nuclear test.
At the same time, the deployment of an American missile defence system in South Korea to protect its ally against an unpredictable North has angered China, which fears it will weaken its own ballistic missile capabilities and says it upsets the regional security balance.
The North's state media has been running stories about the plot since last week.
There are 10 such existing centres in the Central Intelligence Agency, and the new addition will be the most focused in terms of geographical area and remit - the Korean Peninsula now falls under the jurisdiction of the Mission Centre for East Asia and Pacific.
"Our nuclear power is our sovereign right". Pyongyang accused South Korea and the United States of plotting to assassinate the leader using biochemical poison.
As North Korea has been puzzled over whose side China is on in the North-U.S. crisis, ties between them have taken major hits.
While Russia and North Korea have previously sought closer ties on the basis of their mutual isolation from the West, the two pariah states could soon enjoy an even closer cooperation in the wake of the public spat between the USA and North Korea over the latter's planned sixth nuclear weapons test.
A "Korean-style anti-terrorist attack will be commenced from this moment to sweep away the intelligence and plot-breeding organizations of the USA imperialists and the puppet clique".
"North Korea disrespected the wishes of China & its highly respected President when it launched, though unsuccessfully, a missile today". The new president even said that he would be willing to meet Kim Jong-un if it meant bringing lasting peace.