Former Cabinet Legislation Bureau chief Ichiro Komatsu died early Monday, Chief Cabinet Secretary Yoshihide Suga announced. He was 63.

Komatsu served as a senior legal aide to Prime Minister Shinzo Abe, who installed him, and supported Abe's ongoing attempt to reinterpret the pacifist Constitution to sidestep Article 9 and allow Japan to play a greater security role overseas.

"He fulfilled his role up to his physical limits," Suga said at a news conference, praising him for his sincerity. Suga declined to disclose the cause of death at the request of Komatsu's family.

Komatsu stepped down from the post in mid-May due to ill health. He was suffering from cancer and had been briefly hospitalized in January.

In August 2013, Abe installed him as director-general of the influential Cabinet Legislation Bureau, which examines all government-sponsored legislation, legally advises Cabinet members and conducts research on laws and their implementation. It is highly influential in determining how the government can interpret the Constitution.

A former ambassador to France who was widely known as an advocate of reinterpreting the Constitution, Komatsu became the first Foreign Ministry official to fill the post after being unilaterally appointed by Abe, who apparently desired a like-minded legal adviser who could pave the way.

Komatsu was born in 1951 and joined the Foreign Ministry after leaving Hitotsubashi University. He served as director-general for international legal affairs and in other positions.