In a rare move, Chief Cabinet Secretary Yoshihide Suga criticized a new Supreme Court justice Wednesday for appearing to express reservations about Prime Minister Shinzo Abe's drive to reinterpret the Constitution.

"I feel great discomfort," Suga said after Justice Tsuneyuki Yamamoto appeared to suggest Abe should try to amend the Constitution instead of reinterpreting it simply to lift the self-imposed ban on collective self-defense.

Without a relevant ruling by the court, it is up to the Cabinet to "unambiguously" interpret the Constitution, using expertise from the Cabinet Legislation Bureau, which just replaced its chief on Abe's orders, Suga said.

The bureau's previous chief was Yamamoto, who was replaced earlier this month by Ichiro Komatsu, who is reportedly on the same page with Abe. The bureau helps the government with legislative issues, including the interpretation of laws.

Komatsu, a former ambassador to France, is believed to back Abe's goal to reinterpret the Constitution in a way that would allow Japan to exercise its U.N. right to collective self-defense, which is banned by the current interpretation of war-renouncing Article 9.

At his inaugural press conference Tuesday as the Supreme Court's newest justice, Yamamoto said: "When a law remains unchanged, changing the interpretation of it is very difficult," adding, "A constitutional amendment may be appropriate" if the government is to exercise the right to collective self-defense.

While known as an advocate of revising the Constitution to enhance Japan's defenses, Abe is likely to choose the easier route of changing its interpretation.