The presidential office said on Sunday that the chief of the U.S. Indo-Pacific Command recently said the introduction of nuclear-powered submarines (SSNs) in South Korea could be considered in the future depending on its operational analysis.

Commander Adm. Samuel Paparo made the remarks last Friday during an interview with a South Korean media outlet on the occasion of the Rim of the Pacific Exercise.

The commander reportedly said that if the operational analysis leads to confidence on the matter, then the allies can move forward at a later date. 

Paparo said that as allies and partners, it’s important for South Korea and the U.S. to find the most efficient and effective ways to combine their capabilities in ways that most effectively defend their alliances and partnerships.

It’s unusual for a top U.S. military official to mention the possibility of the introduction of nuclear-powered submarines in South Korea. 

Paparo, however, refused to elaborate on the matter, saying that he has no further comment on the issue at this time.