The idea of partially classifying Japan's national defense guidelines, under a major policy review of the country's security by year-end, is being floated to better deal with increased regional security threats by China and Russia, government sources have said.

Making the revised version of the National Defense Program Guidelines, a 10-year defense buildup policy, confidential would be in line with the mostly classified U.S. National Defense Strategy and enable Japan to be more specific in its strategy toward contingencies also involving North Korea, the sources said Saturday.

The guidelines, which are now publicly available, are one of three documents the government is reviewing by the year-end, with a focus on the politically sensitive issue of whether Japan can acquire counterstrike capabilities to attack enemy bases given its exclusively defense-oriented policy under the war-renouncing Constitution.