Unable to land the big deal with Congress to curb drug costs, President Donald Trump on Friday moved on his own to allow imports of cheaper medicines, along with other limited steps that could have some election-year appeal.

'Nothing like this has ever been done before because Big Pharma, with its vast power, would not let it happen. Expensive Insulin went from big dollars to virtual pennies,' Trump bragged on Twitter on Saturday. 

'Epi-pens went from their incredibly high, jacked up prices, to lower than their original give away bargains. Biggest price reductions in history, by far!'

At a White House ceremony, Trump signed four executive orders. One was about importation. The others would direct drugmaker rebates straight to patients, provide insulin and EpiPens at steep discounts to low-income people, and use lower international prices to pay for some Medicare drugs.

Trump cast his directives as far-reaching, but they mostly update earlier administration ideas that have not yet gone into effect.

'I'm unrigging the system that is many decades old,' he declared at Friday's ceremony, promising 'massive' savings.