China's Global Times Newspaper on Sunday said the country's first aircraft carrier, the Liaoning, entered into the South China Sea on Saturday April 10 after completing a week of naval exercises around Taiwan. 

The Liaoning's arrival in the South China Sea came after a US Navy strike group, together with the aircraft carrier USS Theodore Roosevelt and amphibious assault ship USS Makin Island, conducted exercises in the South China Sea a day earlier. 

The two big warships were joined by a cruiser, destroyers and smaller amphibious ships.

The ships also carried hundreds of Marine ground forces from the 15th Marine Expeditionary Unit as well as helicopters and F-35 fighter jets.

"This expeditionary strike force fully demonstrates that we maintain a combat-credible force, capable of responding to any contingency, deter aggression, and provide regional security and stability in support of a free and open Indo-Pacific," US Navy Capt. Stewart Bateshansky, commodore, Amphibious Squadron 3, said in a statement.

According to Reuters, on Monday, April 12, more than 1,700 US and Philippines troops will begin two weeks of military exercises.

The drills will focus on testing the readiness of US and Philippine troops to respond to attacks and natural disasters, the Reuters report said.

The US and the Philippines are tied by a mutual defense treaty, where both countries come to the aid of one another in case of an attack by China.

 Military officials believe it won't be long till the defense treaty is put you test as Chinese vessels plan to enter the Whitsun Reef, owned by Phillipines but claimed by China.

China claims almost all of the 1.3 million square mile South China Sea as its sovereign territory, despite claims from the Philippines, Japan, Taiwan and other Asian countries .