Washington DC - President Donald Trump's trade war will see huge tariffs imposed on pharmaceutical companies operating overseas, triggering a fear that market turbulence could hit the price of medicine.

Trump took to the stage on Tuesday at the National Republican Congressional Committee's (NRCC) annual dinner in Washington DC to announce a "major" tariff against pharmaceutical companies operating overseas.

"We're going to tariff our pharmaceuticals and once we do that, they're gonna come rushing back into our country because we're the big market," Trump said.

"The advantage we have over everybody is that we're the big market, so we're going to be announcing very shortly a major tariff on pharmaceuticals," he revealed.

Tattoos Ink addict Remy speaks out about his radical body mod journey

Last week, Trump announced a global trade war against most of the world, with sweeping tariffs that has since seen China targeted with more than 100% levies on imports into the US.

One of few exemptions in the tariff announcement were pharmaceutical companies, which Trump said would "come roaring back" to the US.

"They’re coming roaring back, they’re all coming back to our country because if they don’t, they got a big tax to pay," he said last week, foreshadowing what was announced last night.

Trump did not reveal the rate of the levy he intends to impose on pharmaceutical companies, but it is likely to be at least 10% and has been labeled as ineffective by experts.

"While the details are scant, we are strongly opposed to tariffs on any pharmaceuticals," BMO Capital Markets analyst Evan Seigerman told Reuters. "These will likely do little to shift manufacturing back to the U.S."

"Given the complexity of the pharma supply chain, we do not expect the industry to make any major changes," Seigerman said.

A tariff imposed on pharmaceutical goods works ultimately as an additional tax on the products, triggering fears that medicine costs could increase in the US as a result of Trump's policy.