Mattis warns of consequences if Beijing keeps militarizing the South China Sea

SINGAPORE (Dow Jones) – The US and China appear to be headed for a more confrontational relationship in Southeast Asia as Washington warns of a more aggressive response to the militarization of disputed islands in the South China Sea.

Speaking at the Shangri-La Dialogue, a regional security conference, US Defense Secretary Jim Mattis warned there could be "much larger consequences" in the future from China's moves to install weapons systems on islands in the sea. He didn't specify what the consequences would be.

The warning, in response to a question from an audience member, came after a speech by Mattis in which he said "despite China's claims to the contrary, the placement of these weapons systems is tied directly to military use for the purposes of intimidation and coercion."

He also called his decision to not invite China to the biennial Rim of the Pacific exercise, slated to begin later in June, "an initial response" to its increased militarization of the South China Sea.

His comments were the most assertive yet in response to what he has described as a ramp-up of Chinese military activity in the past month. This appeared to lay the groundwork for an increased US military–or even economic–response.

Beijing's activities are "in stark contrast to the openness of what our strategy promotes; it calls into question China's broader goals," Mattis told a packed house of international military officials, senior global lawmakers, experts and others on Saturday.

"Our objective remains the complete, verifiable and irreversible denuclearization of the Korean Peninsula," Mattis said, making no mention of maintaining the Trump administration's maximum pressure campaign, which included tough sanctions. Hours earlier, after a White House meeting with a top North Korean official, Gen. Kim Yong Chol, Trump said he would no longer use the term.