CNN – It’s a growing problem that has United States naval commanders scratching their heads: How to keep up with China’s ever-expanding fleet of warships.

A potential solution is within reach, if the US is prepared to think outside the box.

Allies in South Korea and Japan are building some of the highest spec – and affordable – naval hardware on the oceans. 

Buying ships from these countries, or even building US-designed vessels in their shipyards, could be a cost-effective way of closing the gap with China.