A political outcry in Seoul has forced South Korea and Japan to put an intelligence sharing pact on hold less than an hour before it was due to be formally signed, in a major embarrassment for both countries.

The military pact, the first between Japan and South Korea since the second world war, had been seen as a breakthrough between two neighbours with a difficult history. Shortly before the signing was postponed on Friday, Japan's foreign minister had called the agreement a historic event.

The agreement caused uproar in South Korea, which was ruled by Japan as a colony for several decades until the end of the second world war. Critics say the government in Seoul, fearing a backlash from opponents who don't trust Japan, had pushed the pact through without allowing enough public debate.

Japan's cabinet approved the pact on Friday, after South Korea's approval earlier in the week. But Seoul backtracked, saying it would hold off on the formal signing ceremony because of concerns among South Koreans.

Japan's foreign ministry said the ceremony was postponed because of a request from Seoul.

"This is an agreement that we think is very important," said Noriyuki Shikata, deputy cabinet secretary for public relations. "Our view is that we still want to sign it."

Seoul has often been wary of Japan's postwar military development, but the nations have many shared concerns, particularly North Korea and China.

The pact would establish a framework for sharing intelligence in such areas as missile defence, North Korea's nuclear weapons programme, Chinese military operations and other regional security matters.