Japan must undertake a major review of the way its decades-long alliance with the United States works and adopt a more proactive approach toward its top ally after Donald Trump takes office in January, a veteran Diet member said Monday in Tokyo.

Come next year, "Japan can't just sit back and do what it's told to do by the United States. We must make active proposals and swiftly reform our foreign policy where necessary. Otherwise, we shouldn't try and embark on what will become a very tough negotiation" on various issues with the U.S. under Trump, Shigeru Ishiba, a heavyweight in the ruling Liberal Democratic Party, said at the Foreign Correspondents' Club of Japan.

Ishiba, a former defense minister and LDP secretary-general, met with Michael Flynn, a retired U.S. Army lieutenant general newly appointed as Trump's national security adviser, a month before the historic Election Day.