North Korea's provocative launch of a missile through Japanese airspace came quickly following strong warnings from South Korea that its military was gearing up to hit North Korea back hard if necessary.

South Korea and Japan condemned the latest Tuesday's launch in strong terms.

While Japanese Prime Minister Shinzo Abe said the missile was an unprecedented, serious and grave threat to his country, South Korean President Moon Jae-in ordered a show of "overwhelming" force against Pyongyang.

According to South Korean news agency Yonhap, Moon issued the order for his military to display its capabilities just hours after the recent launch. That demonstration included dropping several bombs at a range near the inter-Korean border, Yonhap said, citing Moon's chief press secretary.

South Korea's military issued a warning following the launch, with a spokesman saying it was prepared to initiate "resolute" retaliation if North Korea remained belligerent.

On Monday, Moon had urged defense officials to step up military reform in case the North "crosses the line," local media reported.

Moon told officials to "strongly push" for the military to "meet the requirements of modern warfare so that it can quickly switch to an offensive posture in case North Korea stages a provocation," according to South Korean news agency Yonhap.