The US government has condemned China over collisions between China Coast Guard vessels and Philippine patrol ships in the disputed South China Sea.

The US Department of State said in a statement on Monday that the US "stands with its ally the Philippines and condemns the dangerous actions" by China. It calls on China to abide by international law and desist from dangerous and destabilizing conduct.

The statement also said the US-Philippine Mutual Defense Treaty "extends to armed attacks on Philippine armed forces, public vessels, or aircraft, including those of its Coast Guard - anywhere in the South China Sea."

The China Coast Guard claimed on Monday that Philippine patrol ships "illegally intruded" into waters near Sabina Shoal in the Spratly Islands.

China said one of the Philippine vessels deliberately collided with a Chinese ship.

In response, the Philippine government released images purporting to show damage its vessels sustained in the collisions.

It said two of its patrol vessels encountered unlawful, dangerous maneuvers from Chinese ships while on their way to deliver supplies to Philippine sea-based facilities.