The defection of North Korea's No. 2 diplomat in London will likely prompt the regime in Pyongyang to take oppressive measures to prevent similar cases, which could in return encourage even more defections, a US think tank said Thursday.

Thae Yong-ho, 55, minister at the North's mission in London, recently arrived in South Korea with his family, Seoul's Ministry of Unification announced earlier this week without unveiling further details. He is one of the highest-ranking North Korean diplomats to defect to Seoul.

"This latest defection will also likely cause Kim Jong-un to crack down even further on defections from North Korea. This could mean increasing surveillance and security measures taken in DPRK embassies and North Korean overseas workers' compounds around the world," the Center for Strategic and International Studies said.

"Without a change in conditions, pressure applied by the regime in turn could into a vicious cycle causing even greater numbers of people to defect," the think tank said in a report on its "Beyond Parallel" website dedicated to Korean issues.

Victor Cha, Korea chair at CSIS, said that Thae's defection "represents the flight of some of the North's best and brightest -- their diplomatic cream of the crop."

"The Embassy in London is reserved only for some of the foreign ministry's top officials -- such as current foreign minister Ri Yong-ho (formerly Ambassador) and current ambassador Hyun Hak Bong - with a mastery of the English language such that they can propagate their position to Westerners," Cha said.

CSIS said Thae's defection "may indicate greater amounts of dissatisfaction with Kim Jong-un and the regime."

"If increasing numbers of elites make a rational choice to abandon North Korea because of fears of punishment and an uncertain future, the Kim Jong-un regime will be in significant trouble," the report said.

The high-ranking defection also could mark an intelligence bonanza for South Korea, it said.

"Given that Thae was (ironically) reportedly in charge of tracking North Korean defectors in the UK and was also a minister at the embassy, he may be able to provide key information about how North Korean embassies work to raise foreign currency and transfer funds back to the Kim regime in Pyongyang," it said. (Yonhap)