North Korea is reportedly having difficulties securing re-entry technology for its intercontinental ballistic missile(ICBM) program. 
 
South Korea's National Intelligence Service(NIS) reportedly said on Thursday during a session of the parliamentary intelligence committee that North Korea has conducted missile engine tests multiple times, but has yet to fully perfect the technology to build ICBMs. Yonhap News said a member of the committee conveyed the remarks. 
 
The North is said to be having trouble developing a reliable re-entry vehicle robust enough to resist the heat and pressure of penetrating the atmosphere, which is considered a major hurdle for Pyongyang in its quest to develop an operational ICBM.
 
The NIS attributed the North's hiatus of provocations to global sanctions and pressure and financial difficulties from frequent missile tests.

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