U.S. House Speaker Nancy Pelosi released proposed legislation on Thursday that would allow the federal government to negotiate the prices of hundreds of prescription drugs for Medicare healthcare beneficiaries as well as other consumers.

Americans pay the highest prices for prescription drugs in the world, as most other developed nations have single-payer systems with the government negotiating prices for its people.

Democrats promised to curb prescription drug prices during last year’s congressional election campaign, when they won the majority in the House of Representatives. U.S. President Donald Trump has also promised to lower prices but has been struggling to deliver on that before the November 2020 election.

But many of Trump’s fellow Republicans, who run the Senate, are not keen on letting the government negotiate over prices, saying it amounts to price fixing. Elements of Pelosi’s plan are also opposed by the pharmaceutical industry.

Pelosi’s proposal would allow the U.S. government every year to negotiate prices on “as many as possible of the 250 most costly drugs to Medicare and the entire U.S. health system” that lack price competition, a summary of the bill said.

In the first year alone, drugs representing more than half of all Medicare “Part D” drug spending would be subject to the negotiation process, including insulin, it said.

“To deliver maximum savings for the greatest number of Americans, the price determined by the negotiations process would be available to all purchasers - not just Medicare beneficiaries,” the summary said.