TOKYO — Prime Minister Shigeru Ishiba on Friday promised to strengthen Japan’s defenses amid rising regional and global threats, including from China, while also vowing to work for mutually beneficial ties with the regional giant.

The veteran politician addressed senators in his first policy speech to the lower house of parliament since taking office on Tuesday. His election as prime minister by the Diet came after he was chosen as leader of the ruling Liberal Democratic Party in a vote a week ago.