The United States sailed two of its warships, USS Spruance and USS Preble, close to the disputed Spratly Islands on Monday.
The movement was carried out as part of what the US Navy labels as a "freedom of navigation operation".
"(The Operation was carried out) to challenge excessive maritime claims and preserve access to the waterways as governed by international law," the spokesman for the US Navy's 7th Fleet, Commander Clay Doss told CNN.
"All operations are designed in accordance with international law and demonstrate that the United States will fly, sail and operate wherever international law allows. That is true in the South China Sea as in other places around the globe," he added.
The USA had, in January this year, sailed another warship, USS McCampbell, within 12 nautical miles of the Paracel Islands in the South China Sea.
China, in retaliation, had deployed missiles "capable of targeting medium and large ships," accusing the United States of trespassing its territorial waters. Beijing is yet to respond to Monday's event.
"The US action violated the Chinese laws and international laws, infringed China's sovereignty, damaged regional peace, security, and order. China will take necessary actions to protect state sovereignty," Foreign Ministry spokesperson Lu Kang had said after the January incident. (ANI)