Since President Donald Trump took office in January, the world's two biggest economies have been locked in a tit-for-tat tariff war, with the US now charging levies of up to 145 percent on imports from China.

Beijing has reacted furiously to what it calls unlawful "bullying" by Washington and has imposed retaliatory duties of 125 percent on US imports, dismissing further hikes as pointless.

Bloomberg News reported Tuesday that China had also ordered airlines to halt deliveries of Boeing planes, citing people familiar with the matter.

Beijing has also told its carriers to suspend purchases of aircraft-related equipment and parts from US companies, the financial news outlet reported the people as saying.

AFP has contacted Boeing and China's foreign ministry for comment.

Beijing's reciprocal tariffs on US imports would likely have triggered significant rises in the cost of bringing in aircraft and components.

Bloomberg said the Chinese government is mulling helping carriers that lease Boeing jets and face higher costs.

Trump's fusillade of tariffs has roiled world markets and upended diplomacy with allies and adversaries alike.

The mercurial US leader announced an abrupt freeze on further hikes last week but gave Beijing no immediate reprieve.

US officials on Friday announced exemptions from the latest duties against China and others for a range of high-end tech goods such as smartphones, semiconductors and computers.