Health Minister Mark Butler says the government is seeking clarity about Donald Trump’s plan to slap tariffs on pharmaceuticals.

Trump has flagged a possible 200 per cent tariff on pharmaceuticals — one of Australia’s biggest exports to the US — threating impose it as soon as August 1.

It’s despite the US president previously saying manufactures would have at least a year before they came into affect.

Butler told ABC Radio National Breakfast says it’s been hard to get a clear picture from the US.

“We’re having a little difficulty in understanding the nature and the timing of the plans that the US administration has. Last week, they changed a little bit, even between a couple of interviews I’d given only three hours apart,” he says.

He says at the end of the day the tariffs will just mean US patients will be paying more for “the blood and plasma products in particular that constitute the vast bulk of the exports we send from Australia to the United States”.

Butler reiterated the government would not negotiate on the Pharmaceutical Benefits Scheme.