In an unprecedented declaration, Prime Minister Shinzo Abe said Wednesday he hopes to see a revised Constitution take effect in 2020, revealing the clearest goal yet of his long-held ambition to amend the national charter, which has remained untouched since its inception seven decades ago.

Abe's statement came as the nation marked the 70th anniversary of the enforcement of its pacifist Constitution, which was drafted by the Allied forces after Japan's defeat in World War II.

"2020 is the year when a new Japan will kick off, and I strongly hope the year will see the new Constitution come into force," he said in a video message shown at an event in Tokyo's Nagatacho, the political heart of the country.