Toru Hashimoto, an adviser to the Japanese opposition party Nippon Ishin no Kai, asked the United States on Monday to apply "strong pressure" on Japan to change ordinary people's perceptions about security and the bilateral alliance.

Speaking at a think tank in Washington, Hashimoto said that the political establishment in Tokyo understands the need for Japan to increase its defense spending and play a larger military role within the war-renouncing Constitution, but added that such thinking has not been fully shared by the public.

"We need to change our perception so that we can contribute more to the alliance and contribute more to deterrence," the former Osaka mayor said, alluding to China's assertive territorial claims and North Korea's nuclear and missile threats. "We need to change the public's perceptions.

"So my proposal today was to ask the United States to throw a fastball at us, shake up the situation and apply strong pressure to us," Hashimoto told the Center for Strategic and International Studies.

The election of President Donald Trump — who on the campaign trail threatened to withdraw U.S. forces from Japan and other allies unless they pay more for their defense — has given Tokyo "a chance to examine our thoughts and perception on our security," according to Hashimoto.

"President Donald Trump could say tomorrow we are going to withdraw our forces from Japan. I think that that would be very helpful for us to change the perception of our people," he said.

Hashimoto was visiting Washington for talks with U.S. lawmakers and experts.

After ending a four-year stint as Osaka mayor in 2015, Hashimoto took up a position as an adviser for legal and policy affairs to Nippon Ishin no Kai. Before becoming mayor he spent almost four years as Osaka governor.