Investing.com-- Chinese airlines and Boeing Co (NYSE: BA ) have been severely hurt by U.S. trade tariffs, which have disrupted supply chains and sparked uncertainty, the China’s Commerce Ministry said on Tuesday.

The statement was issued in response to recent media reports that Boeing had flown back several planes that were set to be delivered to Chinese airlines- a trend that heralds much higher costs for the struggling planemaker.

The Commerce Ministry said U.S. tariff threats stood to severely disrupt global supply chains and the aviation market, and that Chinese airlines and Boeing both suffered from “trade investment obstacles.”

The ministry called on the U.S. to create a stable environment for trade and investment.

Media reports over the past week showed Boeing was looking to resell dozens of planes it can no longer sell in China due to trade tariffs imposed by Beijing in retaliation for U.S. duties.

China imposed trade duties of up to 125% on U.S. imports, in retaliation for the 145% duty levied by U.S. President Donald Trump on Beijing earlier this month.

The move marked a renewed escalation in a trade war between the world’s biggest economies, with analysts warning that both sides faced dire economic headwinds from prolonged tariff exchanges.

Trump has claimed that his administration is in talks with China, while Beijing said that no trade negotiations had taken place.