NEW : A Maduro official says the plane was approved to clear U.S. airspace . Venezuelan officials say the Venezuela denied airspace permission to their presidential plane . U.S. 's president says the U.S. also denied Maduro delegation visas . U.N. calls the move a `` serious offense ''
NEW : A State Department official says the plane was approved to clear U.S. airspace . Venezuelan officials say the U.S. denied airspace permission to their presidential plane . Venezuela 's president says the U.S. also denied U.N. delegation visas . Maduro calls the move a `` serious offense ''