Japan has raised its caution level about North Korea’s missile capability, saying in a defense report that the country resumed missile tests while taking no concrete denuclearization steps and had succeeded in making miniaturized warheads, Associated Press reports.

The annual defense paper, approved Friday by the Cabinet, underscores Japan’s fear of being targeted by its neighbor. Its reaction to the North’s recent tests contrasts with a low-key response from the United States.

“Taking into consideration its technological maturity acquired by nuclear tests, North Korea seems to have already achieved miniaturization of warheads to place atop ballistic missiles,” said the report, which last year only mentioned it as a possibility.

North Korea’s military activity “still poses serious and imminent threat” to Japan’s security as well as international peace and safety, it said.

North Korean missiles with those flight ranges could strike targets in Japan and South Korea but not the U.S., which has been the basis for the low-key Trump administration reaction.

“Naturally, we must be fully prepared to defend our country from North Korean missile threats, and we will continue to push forward our preventive measures,” Defense Minister Taro Kono said at a news conference Friday.

The defense report also noted China’s threat is expanding into space from the regional seas, and said Japan must prioritize space security. China was mentioned as a second significant nation after the U.S., the ally and most important nation for Japan.

“China, whose defense budget has been rapidly on the rise, now is almost neck to neck with the United States, becoming major powers in the area of defense,” Kono said.