Japan has criticised as "extremely regrettable" Washington's decision to remove North Korea from its list of state sponsors of terrorism, BBC reported.
Japanese Finance Minister Shoichi Nakagawa told Japanese media that "abductions amount to terrorist acts".
Japan wants action on people it believes were kidnapped by Pyongyang.
The US removed North Korea from its terror list after saying the North had agreed to provide full access to its controversial nuclear programme.
Mr Nakagawa objected to the move during a visit to Washington, where he is attending G7 talks.
Tokyo argues North Korea should remain on the list because issues related to the abduction of Japanese citizens in the 1970s and 1980s have not been resolved.