TOKYO, July 22 (Xinhua) -- Japanese Prime Minister Shinzo Abe said Monday that he will be more flexible for future debates in parliament on revising Japan's Constitution.

Abe made the remarks in a news conference a day after pro-amendment forces suffered a setback in failing to achieve a two-thirds majority in Sunday's upper house election.

"Although we have provided a basis for debate, which we believe is the best, we want to have flexible discussions without sticking to our proposal," Abe said in the press conference.

"I am certain that serious debates will take place regardless of positions of the ruling and opposition parties," he said, adding that he wants to draw a constitutional revision plan that could be approved by the Diet.

Constitution amendment requires two-thirds majorities in both chambers and simple-majority support in an eventual national referendum.

The ruling Liberal Democratic Party and its coalition Komeito ally, coupled with other factions intent on amending Japan's pacifist Constitution, which secured 81 seats in total in the poll for the upper caucus.

Abe's career goal, before and through his two tenures as prime minister, has been to revise the war-renouncing Article 9 of the supreme law, which bans the maintenance of war potential and the use of war as a means of settling international disputes.

Those opposed to the move, however, believe that such a revision will be used to bolster Japanese forces and their international footprint, in contrast to the pacifist stance of the constitution.

In total, when including the seats that were uncontested, the coalition and supporters garnered 160 seats, below the 164 needed in the upper chamber for a call to be initiated to amend the pacifist Constitution ahead of a public referendum on the matter.