Japan's prime minister has inaugurated a panel tasked with reviewing her country's security and defense policies as tensions escalate with China, North Korea and Russia ramping up their military footprint in the region.

It's part of a push by Sanae Takaichi, who took office in October last year, to accelerate Japan's military build-up as a deterrence against regional threats. She argues that Japan needs to prioritise its defense strategy to further strengthen its military capability to better protect itself and survive “prolonged, new forms” of warfare.

Last week, Takaichi's Cabinet scrapped restrictions on Japanese lethal weapons exports, a move welcomed by the United States and other defence partners as a step to deepen their military and industry cooperation.

However, it was criticised by pacifists at home and China for deviating from Japan's postwar self-defence only principle.

“The international situation has completely changed," Takaichi told a meeting at her office on Monday. "The relatively stable post-Cold War international order has become a thing of the past.”

Japan needs to “learn the lesson” from Russia's invasion of Ukraine and the ongoing war in the Middle East and adapt to new forms of warfare, including the use of drones, and be prepared for a long-term conflict, Takaichi said.

"As the world enters an era of turbulence and Japan faces many challenges, the upcoming revision... is a crucial effort that affects Japan's fate," she said.

The 15-member panel of experts in diplomacy, defence and economy will review security and defence policies in light of possible emergency scenarios, and also look at the defense budget and funding before compiling their recommendations for changes in the coming months.

According to existing policies, adopted in December 2022, Japan aims to double its defense spending to 2% of the country's gross domestic product – an amount of about 43 trillion yen (US$270 billion) – through 2027.

Takaichi's government has already reached that spending target and the panel is expected to discuss possible further increases in military spending.