Trade uncertainty caused by the trade war between the US and China could lower the world's gross domestic product (GDP) by 2021, according to a new report.

The document, published by Bloomberg Economics, said global GDP may fall by 0.6 per cent in 2021 relative to a scenario in which there was no trade war.

This amounts to double the direct impact of the tariffs themselves and the equivalent of $585 billion (€528 billion) being wiped off the world GDP of $97 trillion estimated by the International Monetary Fund for 2021.

A forecast 0.6 per cent would come off the US's GDP, while China would also be hit hard with a drop of one per cent.

Bloomberg Economics said that although monetary policy could be used to respond to weakness, world GDP would still be 0.3 per cent lower in 2021 than it would were there no trade war at all.

Speaking at the weekend, US president Donald Trump refuted claims that the US economy is on the brink of recession and insisted "China is eating the tariffs".