Once that happened, he assessed that China would be able to use the bases to challenge the United States' presence in the region, and concluded that China could use the bases to overwhelm any of its neighbors in the South China Sea, and control the region in all scenarios short of war with the United States.
Senator Leila de Lima accused the Armed Forces of the Philippines (AFP) of "playing monkey", while China ramps up its militarization of the West Philippine Sea with its installation of cruise missiles inside the Philippines' exclusive economic zone.
CNBC reported this week that China has quietly deployed cruise ship missiles and surface-to-air missiles on Fiery Cross (Kagitingan) Reef, Mischief (Panganiban) Reef and Subi (Zamora) Reef in the Spratly Islands, all of which are in the exclusive economic zone of the Philippines. Earlier this year, official statements from China's Ministry of Foreign Affairs and editorials in state papers foreshadowed that China might deploy more substantial forces to the Spratly Islands, ostensibly in response to threat from USA warships and plans conducting freedom of navigation operations in their vicinity.
On Thursday, the White House warned Beijing that there will be consequences for its growing militarization in the South China Sea.
"We've raised concerns directly with the Chinese about this and there will be near-term and long-term consequences", Sanders said.
Sanders did not say what the consequences might be.
Six Pacific nations including Brunei, Malaysia, Philippines, Taiwan and Vietnam have territorial claims in the South China Sea that is believed to have huge deposits of oil and gas.
China's defense ministry did not respond to a request for comment.
Experts noted that the move would mark the first Chinese missile deployment in the Spratly Islands, a series of small inlets and reefs that Beijing has slowly built into militarized, artificial islands.
"Those who do not intend to be aggressive have no need to be anxious or scared", ministry spokeswoman Hua Chunying said.
"We are concerned with the reported China's missile deployments over the contested areas in the West Philippine Sea", Presidential Spokesperson Harry Roque said in a press statement. "Be that as it may, we would explore all diplomatic means to address this issue", he said.
Foreign Affairs Minister Julie Bishop said the Australian Government would be "concerned" if the reports were accurate.
"China of course has a unique responsibility as a permanent member of the [UN] Security Council to uphold peace and security around the world and any action to militarise unilaterily features in the South China Sea would go against that responsibility in that role".
CNBC said the YJ-12B anti-ship cruise missiles allowed China to strike vessels within 295 nautical miles. Estimates for the YJ-12's range vary from 160 to 250 nautical miles, though some claim it can reach almost 300, and the HQ-9B's range is believed to be around 100 nautical miles.
Gregory Poling, Center for Strategic and International Studies fellow and director of the Asia Maritime Transparency Initiative told CNBC, "This should be seen as China crossing an important threshold".
"It is time that the AFP draw the line between Duterte's mendicant policy towards China, on the one hand, and national defense and security, on the other", she said.