Less than two weeks into his presidency Donald Trump seems to have proved - in an ominous sense for many people in the United States and abroad - that his campaign rhetoric was not just empty promises.

Despite mounting opposition, Trump has signed executive orders to overturn his predecessor's healthcare reform law, withdraw the US from the Trans-Pacific Partnership, build an anti-migrant wall along the border with Mexico, and temporarily ban entry into the US by nationals from seven Muslim-majority countries.

Even though it has so far been spared a direct provocation from the world's sole superpower, China has no reason to be complacent, given what Trump has previously said about it and the hostile views expressed by some of those who make up his team, especially former ExxonMobil CEO Rex Tillerson, who was confirmed as US secretary of state on Wednesday.

Prior to his election victory, Trump vowed to levy massive tariffs on China's exports, label the country a currency manipulator and take a tougher stance against it on the South China Sea.

Trade moves seem already underway. US regulators on Tuesday imposed hefty tariffs on certain washing machines that it said were imported from China at below fair value.

Such tariffs are a double-edged sword though, as they will surely affect US consumers and incur retaliatory countermeasures that will hurt the interests of US businesses.

The same can be said of labeling China a currency manipulator, which is patently false since Beijing has been working to prop up, not depreciate, the yuan's value over the last year.

How seriously the fallout will be, in jobs and investment, will probably determine how far Trump is prepared to go on a confrontational course.

But with its exports now accounting for 13.8 percent of the world's total, compared with 9 percent for the US, China is better positioned for trade frictions.

More worrying though is the possibility of a clash in the South China Sea. Although US oil companies have long coveted exploiting oil and gas reserves in the region, and of course the US navy seeks to maintain its dominance, trying to block China from its own territory as was mentioned by Tillerson at his confirmation hearing would be a recipe for disaster.

China needs to cast aside any illusions it may have had that Trump was just mouthing off to attract votes and instead be prepared for the worst.