Donald Trump has repeated his threat to impose a 100% tariff on all films not made in the US, claiming the American industry had been "stolen" by other countries.

He said on Monday that California had been heavily affected and the levy would "solve this long time, never ending problem".

In May, the US president said he would talk to Hollywood executives about his plan and to begin the process of imposing the levy because America's film industry was dying "a very fast death".

Trump's remarks come as he announced a new wave of tariffs last week, including a 100% levy on branded or patented drug imports as well as 50% levies on kitchen and bathroom cabinets.

Trump said on his Truth Social platform: "Our movie making business has been stolen from the United States of America, by other countries, just like stealing 'candy from a baby.'

"California, with its weak and incompetent Governor, has been particularly hard hit!"

He said the 100% tariff would be imposed "on any and all movies that are made outside of the United States".

Trump did not say when the tariff will come into force. The White House has been approached for a comment.

It was also unclear if the tariffs would apply to films on streaming services, such as Netflix, as well as those shown at cinemas, or how they would be calculated.

Dan Coatsworth, investment analyst at AJ Bell, questioned how such a tax would work given tariffs are typically imposed on goods and said many filmmakers were choosing to shoot films in other countries because of better incentives.

"The threat of 100% tariffs on movies made outside of the US raises more questions than it does answers," he said.

"Filmmakers have been progressively lured by tax incentives that come from shooting movies in other parts of the world, and the Los Angeles film industry has lost its glitz and glamour."

Mr Coatsworth said it would be difficult to define an American-made movie if a film were to be shot in the US but have foreign actors, directors, or funding.

"So it's hard to understand just how Trump intends to impose the levy," he said.

"Theoretically, being forced to produce movies in the US could push up their costs.

"Content makers would pass on this cost to the customer and that could hurt demand for streaming companies and cinema operators."

He said investors did not "appear to see this as a serious threat" at present. Stocks for companies such as Netflix and Disney dipped briefly, then bounced back.

Several recent major films produced by US studios were shot outside of America, including Deadpool & Wolverine, Wicked and Gladiator II.

The US remains a major film production hub globally despite challenges, according to movie industry research firm ProdPro.

Its annual report showed the country saw $14.54bn (£10.94bn) of production spending last year. But that was down by 26% since 2022.

Countries that have attracted an increase in spending since 2022 include Australia, New Zealand, Canada and the UK.