It has become increasingly clear that Iran is making rapid progress toward attaining a nuclear weapons capability as U.S. officials have confirmed the presence of various nuclear sites that Tehran has failed to disclose
US officials discovered nuclear sites by visiting Tehran.
( z1 discover :ARG0 ( z2 person :ARG0-of ( z3 have-org-role :ARG1 ( z4 country :name ( z5 name :op "US" ) ) :ARG2 ( z6 official ) ) ) :ARG1 ( z7 site :mod ( z8 nucleus ) ) :manner ( z9 visit :ARG0 z2 :ARG1 ( z10 city :name ( z11 name :op "Tehran" ) ) ) )