The Taiwan Strait may be the next major diplomatic problem after China’s clampdown on Hong Kong, according to former Foreign Minister Fumio Kishida, one of two declared candidates to serve as the ruling Liberal Democratic Party's next leader.

Speaking in an interview on Friday, just before Prime Minister Yoshihide Suga made a surprise announcement that he was stepping down, Kishida said Japan should seek to cooperate with Taiwan and countries that share its values of freedom, democracy and the rule of law, as authoritarian countries wield more power.

"Taiwan is at the front line of the standoff between the U.S. and China,” he said. "Looking at the situation with Hong Kong and the Uyghurs, I have a strong feeling that the Taiwan Strait will be the next big problem.”