"I think it's time for the United States government to explore the appropriateness of sanctions against Chinese companies involved in the [land] reclamation that has destabilized the South China Sea and has caused massive environmental destruction across this maritime domain," McCain stated.
McCain warned he was worried China would "attempt to expel another country" from the disputed maritime region such as the Second Thomas Shoal or build new infrastructure at locations like Scarborough Shoal.
In response to such a move, McCain urged Washington to "consider clarifying" how US or Philippine forces would respond to an attack on that territory.
"We should also consider further steps for enhancing posture, improving infrastructure, funding additional exercises, pre-positioning additional equipment and munitions and building partner capacity throughout the Asia Pacific region," McCain added.
The area of the Spratly Islands — a group of over 750 islands and reefs that are believed to hold significant oil and gas reserves — is disputed by China and a number of regional countries. Countries laying claim to the islands say they serve as an important commercial shipping route.
In recent days, China has come under scrutiny for allegedly constructing radar installations on the Cuarteron Reef in the Spratly Islands, which is expected to boost the country's surveillance capabilities.