TAIPEI (Taiwan News) — US Navy Chief Admiral Daryl Caudle said he is “not surprised” by Japanese Prime Minister Takaichi Sanae’s warning that a potential Chinese attack on Taiwan could pose an existential threat to Japan, Nikkei Asia reported Tuesday.

Caudle said interpretations of the term “existential” may vary but he understands why Takaichi views the scenario as concerning. He made the comments during an interview with Nikkei and other Japanese outlets.

Takaichi told parliament earlier this month that a conflict over Taiwan could trigger an “existential threat situation,” allowing Japan to take military action. Her remarks have heightened tensions with Beijing and raised questions about Tokyo’s strategic signaling.

The US and Japan have long maintained strategic ambiguity over how they would respond to a Taiwan contingency. Caudle said nothing in Takaichi’s remarks has altered US planning, operations, or maritime coordination with Japan.

He also addressed recent news that Washington has approved South Korea’s pursuit of nuclear-powered attack submarines. Caudle said Seoul’s move could prompt Tokyo to consider similar options but noted such systems require years of planning and debate.

Caudle reiterated that Japan must increase defense spending, echoing pressure from President Donald Trump’s administration. Caudle said he wants Japan to spend 5% of GDP on defense and questioned whether the current 2% target is sufficient.

Tensions over Taiwan have also spilled into diplomatic exchanges between China and the US. Chinese envoys criticized Takaichi’s remarks, prompting a response from US Ambassador to Japan George Glass.

Glass said Chinese criticism only strengthened US-Japan ties. “Looks like Christmas has come early,” he wrote on X.