(DOD photo by Lisa Ferdinando)

Secretary of Defense Jim Mattis called on America's allies to combat Chinese efforts to dominate the contested South China Sea during a trilateral meeting in Singapore Oct. 19, 2018.

"I think that all of us joining hands together, ASEAN allies and partners, and we affirm as we do so that no single nation can rewrite the international rule to the road and expect all nations large and small to respect those rules," Mattis said during a meeting with his Japanese and South Korean counterparts, according to The Hill.


"The United States, alongside our allies and partners, will continue to fly, sail, and operate wherever international law allows and our national interests demand. We will not be intimidated, and we will not stand down, for we cannot accept the PRC's militarization of the South China Sea or any coercion in this region," he added.

Mattis doubled down on statements made by Vice President Mike Pence in a forceful speech at the Hudson Foundation in October 2018 that came immediately in the wake of a showdown between US and Chinese warships.

"China wants nothing less than to push the United States of America from the Western Pacific and attempt to prevent us from coming to the aid of our allies," Pence explained. He called attention to the recent showdown in the South China Sea as evidence of "China's aggression."

An EA-18G Growler assigned to Electronic Attack Squadron (VFA) 141 lands on the flight deck of the Navy's forward deployed aircraft carrier, USS Ronald Reagan.

(U.S. Navy photo by Mass Communication Specialist 2nd Class Kenneth Abbate)

"A Chinese naval vessel came within 45 yards of the USS Decatur as it conducted freedom-of-navigation operations in the South China Sea, forcing our ship to quickly maneuver to avoid collision," he said, describing a dangerous encounter that the US military characterized as "unsafe" and "unprofessional."

The Trump administration has taken a hard-line stance against China, targeting Beijing for perceived violations of the rules-based international order. In the South China Sea, tensions have been running high as the US challenges China through freedom-of-navigation operations, bomber overflights, and joint drills with regional partners — all aimed to counter China's expansive but discredited territorial claims.

A pair of B-52H Stratofortress bombers flew through the disputed South China Sea Oct. 16, 2018, in support of US Indo-Pacific Command's Continuous Bomber Presence mission, which is notably intended to send a deterrence message to potential adversaries.

Mattis met with his Chinese counterpart Gen. Wei Fenghe Oct. 18, 2018, for an hour and a half on the sidelines of a security forum in Singapore. The talks, described as "straightforward and candid," focused heavily on the South China Sea, but it is unclear if the two sides made any real progress on the issue.

"That's an area where we will continue to have differences," Assistant Secretary of Defense for Asian and Pacific Security Affairs Randall Schriver said after the meeting concluded.

This article originally appeared on Business Insider. Follow @BusinessInsider on Twitter.