The Pentagon had been working on a plan for Mattis to travel to Beijing later this month to meet General Wei Fenghe for security talks, but China ultimately declined to make him available, the official told AFP.

In light of that, the decision to scrap the visit came primarily from the US side, the official added.

It would have been Mattis's second trip to China as Pentagon chief, following a June visit when he met Chinese President Xi Jinping, as well as Wei and a number of other officials.

The US embassy in Beijing declined to comment.

The trip cancelation comes as friction between the US and China continues to rise, particularly over trade.

President Donald Trump's trade war has infuriated Beijing, as did his authorization of a $1.3 billion arms sale to Taiwan, which China considers a rebel province.

Washington last week enacted new tariffs against China covering another $200 billion of its imports.

And Washington last month placed financial sanctions on China for its recent purchase of Russian Sukhoi Su-35 fighter jets and S-400 surface-to-air missile systems.

China reacted by scrapping a US warship's planned port visit to Hong Kong and canceling a meeting between the head of the Chinese navy and his American counterpart.

On Sunday, a US warship sailed through waters off the contested Spratly Islands in the South China Sea -- in the latest implicit challenge to Beijing's sweeping territorial claims in the region.

There was no immediate reaction from China, but a similar US operation in July, involving the disputed Paracel islands, prompted a furious Beijing to deploy military vessels and fighter jets.

The Pentagon said all US military operations in the area "are designed in accordance with international law and demonstrate that the United States will fly, sail and operate wherever international law allows."