US officials have not yet commented on, at what stage is the decision.
In his speech at the Singapore summit, US Defence Secretary Jim Mattis said that Beijing's policy in the South China Sea "stands in stark contrast to the openness our strategy promotes".
Speaking on the sidelines of the Singapore conference, He Lei, of the PLA's Academy of Military Sciences, said China had every right to continue to militarize its South China Sea holdings.
"The United States military presence in the South China Sea is greater than that of China and other countries that surround the seas combined", Chinese foreign ministry spokeswoman Hua Chunying said at a regular briefing.
Singapore-based security expert Tim Huxley said while increased pressure might slow China's militarization efforts, they would be hard to stop.
The comments came on the heels of a string of events that highlight the tension between the world's two biggest economies over the South China Sea's disputed waters.
Last month China said it had for the first time landed bombers on Woody Island in the Paracel Islands, prompting U.S. warnings that it was destabilising the region.
The United States will increase naval patrols in the South China sea in an attempt to challenge the growing militarization of China.
China relying on muscle to use weapons to pursue goals not favored by worldwide tribunals " is not a way to make long-term collaboration the rule of the road in a region that's important to China's future", Mattis said, when asked to elaborate more on the consequences.
Wang Mingliang, a defence expert cited in the statement, said the exercises on islands in the were aimed at helping the air force "strengthen its combat capability to deal with maritime security threats".
The U.S., he said, "will continue to pursue a constructive, results-oriented relationship with China, cooperation when possible, and competing vigorously where we must".More news: Drone Saves Man's Life From Kilauea Volcano Disaster in Hawaii
Mattis said there was little doubt about Beijing's intentions.
The South China Sea, a key trade route, is subject to overlapping claims by China, Vietnam, the Philippines, Malaysia, Taiwan and Brunei.
Despite He's admission, he batted back Mattis' accusations, saying that the "close-up reconnaissance" carried out by two U.S. warships - which sailed within 12 nautical miles of the Paracel Islands last week - was the real "source of militarisation" in the region.
Just hours after the U.S. President Donald Trump announced that the highly-anticipated meeting with the DPKR leader Kim Jong Un in Singapore is back on track, U.S. Secretary of Defense James Mattis told a room that withdrawing or reducing military presence in the Korean Peninsula is not now an option.
"I think it goes to a fundamental disconnect between the way the global tribunals have looked at these waters - these waters look to us as free and open waters", said Mattis, addressing last week's freedom of navigation operation directly.
The U.S., he said, remains committed to ensuring free and open transit in the region.
"US support for Taiwan has always been strong [but] we will also have to see how the [US President Donald Trump] administration reacts ..."
Discussion about the number of U.S troops in South Korea is subject to bilateral discussions between Washington and Seoul that are separate from the North Korea negotiations, Mattis said.
Gen He added: "We see any other country that tries to make noise about this as interfering in our internal affairs".
"We've been sending a clear message to all that the freedom of navigation is absolutely critical", he said.