Car companies and suppliers are urging the United States not to impose additional tariffs (to 25%) on their products, saying such a move would result in job cuts, loss of investment and higher prices. Several weeks earlier, US president Donald Trump threatened to increase tariffs on the notion that there was an imbalance in international import duty fees.

The Trump administration has already implemented duties of 25% on imported steel and 10% on aluminium, which affects metals from Canada, European Union, or Mexico, in order to protect domestic producers. The Department of Commerce was even ordered to start an investigation into automobile imports to determine whether they “threaten to impair the national security” of the US.

In reports by The Guardian, Bloomberg, CNBC, Reuters and Fortune, General Motors (GM) warned that expansive US tariffs could lead to the US being isolated from the global market. It adds that tariffs could increase vehicles prices and reduce sales, adding that even if higher costs weren’t passed on the consumers and absorbed, it would still lead to less investment, fewer jobs, and lower wages for its employees.

Meanwhile, Toyota said in an official statement, “a potential tariff on automobiles and parts would have a negative impact on all manufacturers, increasing the cost of imported vehicles as well as domestically produced vehicles that rely on imported parts.”

“Engaging in trade wars with our allies would diminish, not enhance, US national security, jobs and prosperity, and undermine the rules-based global trading system, which has led to a period of unparalleled peace and prosperity in Europe and Asia for the last half century,” it added.

Mazda also chimed in on the Department of Commerce’s Section 232 investigation, saying that tariffs would increase the cost of every new vehicle sold in the US, regardless of where it is built. “As Mazda begins construction of our new auto factory in Huntsville, Alabama, we urge the Commerce Department to reject the premise that auto imports are a threat to national security,” it said.

“It appears that the purpose of threatening to impose these duties is to achieve certain economic objectives, under the theory that enhancing US economic competitiveness will enhance US national security,” BMW said in a letter to US secretary of commerce Wilbur Ross. The German automaker’s plant in Spartanburg, South Carolina is its largest globally and ships more than 70% of its annual production to other export markets. It also supports more than 120,000 jobs.

South Korean automaker Hyundai said it could rethink production of vehicles in the US, joining other companies speaking out against Trump’s crackdown on steel and aluminium imports. “Changes to the existing tariff structure could negatively impact our current US production and further expansion. Imposing tariffs on steel could increase production costs, which could lead to higher prices for US consumers, and, potentially, decreased demand,” said Hyundai spokesman Jim Trainor.

“Tariffs or other trade barriers on imported automobiles and/or automotive parts would weaken the US economy and threaten to undermine the entire US automotive industry,” wrote James Tobin, chief marketing officer at automotive parts supplier Magna International.