The row began when US officials said they were considering sending warships inside the 12-nautical-mile zones that China claims as territory around the Spratlys.
That sparked strong words from China, with Ms Hua warning: "We will never allow any country to violate China's territorial waters and airspace in the Spratly Islands, in the name of protecting freedom of navigation and overflight."
On Tuesday, US Defence Secretary Ash Carter expressed "strong concerns" over island-building, and defended Washington's plans.
"Make no mistake, the United States will fly, sail and operate wherever international law allows, as we do around the world, and the South China Sea will not be an exception," he said at a news conference with the Australian foreign and defence ministers.
"We will do that in the time and places of our choosing," he added, according to Reuters news agency.
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That in turn triggered Wednesday's rebuke from China.
Asked about Mr Carter's comments, Ms Hua said: "I want to point out that some countries, in a region far from their own lands, have deployed offensive weaponry on a large scale and flexed their military muscles again and again in the South China Sea.
"This is the biggest factor in the militarisation of the South China Sea. We hope the relevant countries cease hyping up the South China Sea issue and scrupulously abide by their promises not to take a position on the territorial disputes," she said, according to Reuters.
The guided-missile destroyer USS Lassen breached the 12-nautical mile zone China claims around Subi and Mischief reefs in the Spratly archipelago.
The freedom of navigation operation is a serious challenge to China's claims over the artificial islands.
Its foreign ministry said the ship had been warned and characterised the act as a "threat to China's sovereignty".
Lu Kang, the spokesman, added that Beijing would "resolutely respond to any country's deliberately provocative actions" and that the ship had been "tracked and warned" while on the mission to deliberately enter the disputed waters.
China's naval commander has warned his US counterpart against "dangerous and provocative acts", days after a US warship sailed close to contested islands in the South China Sea.
Admiral Wu Shengli said in a video conference that there was a risk that such minor incidents could spark war, according to a Navy statement.
The US said the talks were productive and that dialogue would be maintained.
China must stop land reclamation in disputed waters in the South China Sea, US President Barack Obama has said.
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Mr Obama earlier pledged monetary and naval assistance to the Philippines, which has competing claims with China in the resource-rich region.
China is bound by the United Nations Convention on the Law of the Sea (UNCLOS), which it has ratified. The law states that sub-sea structures, such as reefs, cannot be claimed as sovereign coastline, and that building artificial structures on top of them does not turn them in to sovereign territory either.
A country that owns a natural island can claim a 12-nautical-mile territorial limit around it, both on the sea and in the air. But artificial structures do not confer any such right. In other words, we would be able to fly our aircraft right up to China's new islands without breaking any international laws, and China should not interfere with our flight.
Xinhua state news agency released pictures of two commercial jets on the Fiery Cross Reef, which it called by its Chinese name Yongshu.
Vietnam and the US protested China's 2 January landing of a plane on the reef.
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Pictures show the planes on a brand-new strip of tarmac at what Xinhua called "our country's most southern airport".
The U.S. Navy's first freedom of navigation patrol of 2016 to counter Chinese territorial claims in the South China Sea has refocused attention on the continuing tensions in East Asia.
The destroyer Curtis Wilbur’s patrol of Triton Island, part of the Paracel Islands chain, on Jan. 30 came a little more than three months after the destroyer Lassen conducted its much-publicized patrol of the Spratly Islands, where China is building artificial islands on top of reefs.
China has deployed surface-to-air missiles on a disputed island in the South China Sea, Taiwan says.
China has accused the US of militarising the disputed South China Sea through its air and naval patrols.
Well, the militarization is actually our fault.
South China Sea: Beijing accuses US of militarisation - BBC News
So, by sailing our navy through international waters, we militarized them.