The latest U.S. threat to impose new tariffs on 300 billion U.S. dollars' worth of Chinese goods could breach WTO rules, said Australian Trade Minister Simon Birmingham in an interview with Sky News on Sunday.

Birmingham said it "may well" be the case that the U.S. would breach WTO rules, The Guardian reported.

Birmingham also expressed "bigger and more immediate concern" on the practical impact of the escalating dispute on global trade volumes, and on global economic growth.

The International Monetary Fund (IMF) in July said the global growth is predicted to be 3.2 percent in 2019 and 3.5 percent in 2020, lower than its April forecast because of the ongoing trade tariffs and Brexit uncertainties. The IMF warned that trade conflicts are weighing on the global economy as business confidence and financial market sentiment have been buffeted.

"That's a significant drop," Birmingham said. "What that is doing is having a dampening impact on the rate of global economic growth, which is bad for jobs and business in China, the United States, in Australia and everywhere."

The U.S. financial market was hit hard and global oil prices plummeted after the latest U.S. tariff threat to China. U.S. retailers warned that additional tariffs will hurt consumer purchases, further raise prices and limit hiring.

Read more: Wall Street tumbles after Trump's new tariff threat

Birmingham visited Beijing during the Regional Comprehensive Economic Partnership (RCEP) ministerial meeting. He said Australia and China will continue to advance a strong trade and economic relationship, underpinned by the high-quality China-Australia Free Trade Agreement.