"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 earlier this month 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."