In an address to the IAEA board of governors in Vienna, Hans Blix said a technical team that visited North Korea last month found that "facilities subject to the freeze were not in operation and that construction work had stopped."
Hans Blix has visited North Korea. 
It doesn't say whether Hans Blix visited himself. He said that a technical team had visited but it is not clear whether he was on it. 
( z1 visit :ARG0 ( z2 person :name ( z3 name :op "Hans" :op "Blix" ) ) :ARG1 ( z4 country :name ( z5 name :op "North" :op "Korea" ) ) )