Austin, Texas - Elon Musk's Tesla has warned that President Donald Trump's trade war could make it vulnerable to retaliatory tariffs and drive up production costs for vehicles made in the US.

In a letter to US Trade Representative Jamieson Greer, Tesla expressed its support for fair trade but cautioned that American exporters were "exposed to disproportionate impacts when other countries respond to US trade actions."

"For example, past trade actions by the United States have resulted in immediate reactions by the targeted countries, including increased tariffs on EVs imported into those countries," the letter, dated March 11, stated.

Additional tariffs imposed by Trump's administration have already triggered countermeasures from Canada and the European Union, among others.

Ariana Grande Ariana Grande and Ethan Slater reportedly considering marriage – but when?

Tesla further said that, despite increasing domestic production, some raw materials and components would still need to be sourced from international markets.

"Trade actions should not (and need not) conflict with objectives to further increase and support domestic manufacturing," the letter said.

The Financial Times reported that the letter remained unsigned, with sources claiming that no one at the company wanted to risk being fired for sending it.

The operates plants in China and Germany, in addition to its US facilities. Its CEO, Musk, is a close ally of Trump who is now leading an aggressive campaign to dismantle large swathes of the administrative state.

Widespread anger at Musk's action have led to a sharp fall in Tesla's share price, with Trump scrambling to support the far-right billionaire by advertising an electric car at the White House.