The USS William P. Lawrence (DDG-110) and USS Ross (DDG-71) Arleigh Burke-class guided missile destroyers sit docked in San Diego, California, April 12, 2015. REUTERS/Louis Nastro

SYDNEY (Reuters) - Australia backed the United States on Thursday in its so-called freedom of navigation operation close to a disputed reef in the South China Sea, a patrol China has denounced as an illegal threat to peace.

U.S. guided missile destroyer the USS William P. Lawrence traveled within 12 nautical miles (22 km) of Chinese-occupied Fiery Cross Reef on Tuesday.

The operation was undertaken to challenge what a U.S. Defense Department spokesman described as excessive maritime claims by China, Taiwan and Vietnam, which were seeking to restrict navigation rights in the South China Sea.

Australia has consistently supported U.S.-led freedom of navigation activities in the South China Sea, where Beijing has been adding land reclamation to islands and reefs in waters claimed by several regional countries.

Australian Prime Minister Malcolm Turnbull told reporters he had reiterated that support in a phone call with U.S. President Barack Obama early on Thursday.

“We ... talked about security issues in our region and confirmed our strong commitment to freedom of navigation throughout the region and the importance of any territorial disputes being resolved peacefully and in accordance with international law,” Turnbull said.

China and the United States have traded accusations of militarizing the South China Sea as China undertakes large-scale land reclamation to create artificial islands and construction on disputed features while the United States has increased its patrols and exercises.

Facilities on Fiery Cross Reef include a 3,000-metre (10,000-foot) runway that the United States worries China will use to press its extensive territorial claims at the expense of weaker rivals.