President Donald Trump will push back against China in the South China Sea if U.S. interests are threatened, and prevent Chinese domination in the region, the White House revealed Monday.“I think the U.S. is going to make sure that we protect our interests there,” White House press secretary Sean Spicer said during the first official presidential press conference for the new administration.

"It’s a question of if those islands are in fact in international waters and not part of China proper, then yeah, we’re going to make sure that we defend international territories from being taken over by one country," said Spicer referring to China's unlawfully claimed and militarized islands in the South China Sea, where an estimated $5 trillion in shipping passes annually. This statement stops short of Tillerson's earlier comment that the US should "send China a clear signal that, first, the island-building stops, and second, your access to those islands also is not going to be allowed."
Tillerson's comment drew fierce rebuke from Chinese state-run media and US-based China watchers as well, with Chinese media saying that "unless Washington plans to wage a large-scale war in the South China Sea, any other approaches to prevent Chinese access to the islands will be foolish."(USS Lassen (DDG 82) patrols the eastern Pacific Ocean.US Navy photo by Mass Communication Specialist 2nd Class Huey D. Younger Jr.) 
At the time, Bonnie Glaser, a senior adviser for Asia and the director of the China Power Project at the Center for Strategic and International Studies, told Business Insider that she heard "from some people on the transition team that he misspoke."Glaser also agreed that Tillerson's suggested moves in the South China Sea were impractical, and that the US would "certainly end up in a shooting war with China."
Chinese media responded by warning that any attempt to prevent China accessing its interests in the region risked sparking a “large-scale war”.At his first question and answer session with the press on Monday Spicer again hinted Trump’s administration would take a harder line on the South China Sea.
“It’s a question of if those islands are in fact in international waters and not part of China proper, then yeah, we’re going to make sure that we defend international territories from being taken over by one country,” he told reporters.Spicer declined to explain how such steps might be enforced. “I think, as we develop further, we’ll have more information on it,” he said.
However, scholars who have been advising Trump’s team on China policy back a more muscular military approach, primarily through a dramatically strengthened navy in the region.“We’ve talked a big game on security but haven’t really followed it up all that well with the military muscle that was needed,” Daniel Blumenthal, the director of Asian Studies at the American Enterprise Institute, a conservative Washington-based thinktank, told the Guardian.
Blumenthal said a “strong, persistent US naval presence” was now required to back up a foreign policy “that at its bottom line says that China’s not going to control the South China Sea … But you can’t do that without military resources.” China claims sovereignty over nearly the entire South China Sea and in recent years has stepped up a campaign to cement its control over a region where Brunei, Japan, Malaysia, the Philippines, Taiwan and Vietnam also have claims.
It has done so partly by transforming a series of remote coral reefs into what experts say are effectively military outposts designed to help enforce its territorial claims. Despite fears about the direction US policy towards China may take under the new president, Blumenthal argued a more robust stance from Washington could in fact improve ties.
“My own view and my own experience in government is that when you are very clear with China about what your national interests are and what you are going to do in the region, they become very clear as well and say, ‘You know what, we’re going to stop pushing’ and the relationship in certain areas can improve.

“I think the most dangerous scenario was the one we were heading towards: a lot of tough talk on the South China Sea, but China continuing to encroach and the United States not really putting a lot of muscle behind the statements it was making.”