THE US has accused China of a continuing a state-backed campaign of intellectual property and technology theft even as the world's two largest economies descended into a tariff war, reports Bloomberg.

Renewed accusations came in a detailed 53-page report released by US Trade Representative Robert Lighthizer's office just 10 days before President Donald Trump is due to meet Chinese President Xi Jinping at the November 30 - December 1 Group of 20 summit in Buenos Aires.

The timing of the report's release appeared to be a move by some of the more hawkish members of Trump's administration, such as Mr Lighthizer, to bolster their case ahead of the summit and as other cabinet members such as Treasury Secretary Steven Mnuchin push for a resumption of negotiations.

"China fundamentally has not altered its acts, policies, and practices related to technology transfer, intellectual property, and innovation, and indeed appears to have taken further unreasonable actions in recent months," the report said.

Moreover the report accused China of continuing cyber-attacks on American companies that were both intensifying and growing in sophistication.

Experts from the US Naval War College and Tel Aviv University found that China Telecom may be engaging in a "malicious" campaign to "hijack Internet traffic and direct it through mainland Chinese servers for possible collection and analysis", the report said.