The prime minister also boarded a British Royal Navy aircraft carrier, currently docked at the US Navy's Yokosuka base, in a bid to highlight cooperation between Japan and Britain.
"To protect our country's independence and peace, we must further boldly advance efforts to strengthen deterrence," Ishiba said in a speech at a hangar of the Kaga, referring to the severe security environment surrounding Japan.
"China is expanding and intensifying its military activities around our country," he said, noting that two Chinese aircraft carriers sailed simultaneously in waters near Japan in June.
"It is necessary for Japan to constantly advance efforts to strengthen its deterrence and response capabilities on its own initiative," the prime minister said, expressing a sense of crisis over moves by Russia and North Korea.
The conversion of the Kaga into a de facto aircraft carrier is part of efforts to strengthen deterrence, he said, adding, "It will contribute to strengthening the defence of the sea and air."
This was the prime minister's first inspection of a destroyer since May, when he visited the MSDF's Maizuru base in Kyoto Prefecture, western Japan, to inspect destroyers.
Speaking to reporters after inspecting the British Royal Navy's HMS Prince of Wales on Saturday, Ishiba said the vessel's port call in Japan demonstrates Britain's commitment to peace and stability in the region.
[Copyright The Jiji Press, Ltd.]