It should be able to. I have a NUC5i5MYHE and it can drive 3840x2160 @60Hz through mini DP 1.2. I have trouble driving dual monitor @ 4K resolution though.
The maximum supported resolution is 3840 x 2160 @ 60 Hz, 30bpp. The Mini DisplayPort is compliant with the DisplayPort 1.2 specification.
More information is available here: http://downloadmirror.intel.com/24565/eng/NUC5i5RYB_NUC5i3RYB_TechProdSpec01.pdf page #22