Tech billionaire and Tesla CEO Elon Musk made direct yet unsuccessful appeals to US president Donald Trump to reverse tariffs over the past weekend, The Washington Post reported on Monday citing two people familiar with the matter.
This exchange marks the highest profile disagreement between the US president and Mr Musk, the report said.
It follows Mr Trump's unveiling of a 10 per cent baseline tariff on all imports to the US along with higher duties on dozens of other countries.
The White House and Mr Musk did not immediately respond to Reuters requests for comment.
Mr Musk, a Trump adviser who has been working to eliminate wasteful US public spending, called for zero tariffs between the US and Europe during a virtual interaction at a congress in Florence of Italy's right-wing, co-ruling League Party over the weekend.
Tesla has seen its quarterly sales drop sharply amid a backlash against Mr Musk's work with a new "Department of Government Efficiency".
The company's shares are trading at $233.29 (€213.45) as of its last close on Monday, down over 42 per cent since the beginning of the year.
Mr Musk has previously said that the impact of US president Donald Trump's auto tariffs on Tesla is "significant".
Economists say the tariffs could reignite inflation, raise the risk of a US recession and boost costs for the average US family by thousands of dollars - a potential liability for a president who campaigned on a promise to bring down the cost of living.
On Monday, Trump adviser Peter Navarro dismissed Mr Musk's push for "zero tariffs" between the United States and Europe, calling the Tesla CEO a "car assembler" reliant on parts from other countries.
Mr Navarro, widely seen as the architect of Mr Trump's tariff plans, told CNBC Mr Musk had done a good job with his work to streamline government, but his comments on tariffs were not surprising given his role as "car person," the latest salvo in a growing feud between the Trump advisers.
"When it comes to tariffs and trade, we all understand in the White House - and the American people understand - that Elon is a car manufacturer, but he's not a car manufacturer. He's a car assembler," Mr Navarro said, adding that many Tesla parts came from Japan, China and Taiwan.
"He's a car person. That's what he does, and he wants the cheap foreign parts."
