The visit followed a USA clampdown on technology giant Huawei by President Donald Trump's administration earlier this month, and was interpreted by experts as a signal that the Chinese government is weighing restrictions on rare-earth exports.
Huawei stepped up its legal battle on Wednesday, announcing it had filed a motion in United States court for summary judgement in its bid to overturn USA legislation that bars federal agencies from using its equipment over security concerns.
State media made it clearer on Wednesday.
The threat to weaponize strategic materials ratchets up the tension between the world's two biggest economies before an expected meeting between Presidents Xi Jinping and Donald Trump at the G-20 meeting next month. "The Chinese people will never accept this!" the ruling Communist Party newspaper added.
"We could see responses on the USA side, perhaps very soon", ARPN's McGroarty said.
"We remind the U.S. not to underestimate China's ability to defend its rights to development and to remember not to blame anyone for not warning them", People's Daily, a Communist Party publication, stated Wednesday.
The Chinese government threatened to limit exports of rare earth elements to America as leverage in the trade dispute.
Shares in the company Xi visited last week, JL MAG Rare-Earth Co Ltd, surged another 10% to a record high on Wednesday, having gained 134.1% in May alone.
An unnamed official from the National Development and Reform Commission, China's state planner, issued a cryptic warning late Tuesday.
China can only play a rare earths embargo card once, both analysts say.
China accounted for 80% of rare earth imports between 2014 and 2017 by the United States, which has excluded them from recent tariffs along with some other critical Chinese minerals.
The bedrock of electrical manufacturing, rare earths are 17 elements that serve as key components in devices ranging from hi-tech smartphones and cameras to flat-screen televisions and computers.
A worker in China shifts soil containing rare earth minerals intended for export in 2010.
He renewed his attack on Huawei, saying there was a "deep connectivity" between the company and the Chinese state that had no parallel in the U.S. system.
Four years earlier, Japanese industry sources said China temporarily cut off exports to Japan in 2010 when a territorial row flared between the Asian rivals, charges that Beijing denied.
But experts say the Japan experience showed that China may not have such strong leverage.
China dominates global exports of the 17 elements that constitute rare earths, accounting for nearly 80 percent of America's imports previous year, according to the U.S. Geological Survey (USGS) and Bank of America Merrill Lynch analysts. Wind turbines and solar panels also depend on rare earth metal imports from China.
"If anyone wants to use the products made from our rare earth exports to try to counter China's development, then the people from the southern Jiangxi Communist revolutionary base would not be happy, and the people of China will not be happy", the NDRC representative said.
The Global Times acknowledged that banning rare earth exports to the USA could "produce complex effects, including incurring certain losses on China itself".