Elon Musk's Tesla has reported a 14% decline in vehicle deliveries in the second quarter of the year, as the electric car-maker's problems show no sign of abating.

The just over 384,000 vehicles it delivered between April and June represents the second quarterly drop in a row.

Tesla faces increasing competition from rivals, including China's BYD. Musk's controversial role as a government efficiency czar in the Trump administration has also been blamed for the plummeting numbers.

Musk has since left the role - but has publicly sparred with US President Donald Trump over a massive spending bill pushed by the White House.

In response, Trump floated cutting the subsidies received by Musk's firms or even deporting him.

Trump suggested that the ad-hoc Department of Government Efficiency - known as Doge - could be used to harm the billionaire's companies.

"Elon may get more subsidy than any human being in history, by far," Trump wrote on social media Tuesday. "Perhaps we should have DOGE take a good, hard, look at this? BIG MONEY TO BE SAVED!!!"

"I am literally saying CUT IT ALL. Now," Musk replied.

Trump has said that Musk's opposition to the spending bill stems from a provision that removes incentives to buy electric vehicles.

"He's upset that he's losing his EV mandate, he's very upset, he could lose a lot more than that, I can tell you that," Trump told reporters on Tuesday.

Though the quarterly deliveries metric is tracked closely by investors, some analysts have shrugged off the figures.

"The good news: that ~14% should mark the bottom," wrote Deepwater Asset Management's Gene Munster on Musk's social media site X. "I have September down 10% and December flat."

Munster said he expected uncertainty about the US EV tax credit to boost near-term sales as buyers scramble to purchase before it expires.

Tesla's push into robotaxis which kicked off in Austin, Texas last month in uncertain fashion could prove critical, he said.

"Over the next two years, I think investors will be fine with flat deliveries as long as autonomy shows measurable progress," Munster added.