Congressional Republicans responded with caution Thursday as President Trump proposed to set Medicare prices for certain drugs based on what foreign countries pay, sharply breaking with GOP orthodoxy.

Republicans in Congress have traditionally opposed the government setting the prices of prescription drugs, and favored using market forces to boost competition and fix high drug prices.

Responding to Trump's speech, GOP Reps. Greg Walden of Oregon and Kevin Brady of Texas, chairmen of the key committees with oversight over drug prices, did not say whether they supported the proposal.

“We commend the president for remaining steadfast in his commitment and appreciate Secretary of Health and Human Services Azar’s efforts to encourage lower drug costs for patients,” the two said in a joint statement, which steered clear of endorsing Trump's proposal.

Sen. Orrin Hatch, R-Utah, chairman of the Senate Finance Committee, was also cautious in a statement his office gave to the Washington Examiner.

“Proposals aimed at addressing prescription drug prices must not hamper innovation or access to new drugs that have the ability to cure diseases,” he said. “I am reviewing the administration’s proposal to make sure it won’t chill innovation or inadvertently disrupt care for vulnerable Medicare beneficiaries.”

Sen. Chuck Grassley, R-Iowa, praised the move, however.

“There’s no reason that Americans should pay more than anyone else for exactly the same medications, especially since so many of these medications were developed and manufactured right here in America,” Grassley said in a statement. Grassley has worked on multiple bipartisan bills to tackle high drug prices, most recently making an attempt with Sen. Dick Durbin, D-Ill., on a bill to force drugmakers to disclose list prices in TV ads.

Trump's proposal is sure to elicit opposition from the pharmaceutical industry, which blasted the proposal as implementing "foreign price controls."

Under Trump’s proposal, Health and Human Services would, over the course of five years, tie the price of certain drugs that Medicare pays for to the price paid by another country. The change would eventually affect a majority of the drugs covered under Medicare Part B, which covers drugs administered in doctors' offices, like vaccines.

Currently, Medicare just pays the average sales price, along with a small percentage of that price to the doctor for storage and handling costs, and has no mechanism to lower prices.

When asked if the proposal was a price cap, HHS Secretary Alex Azar responded that it is “setting a price for what Medicare will pay in this unique program.”

The current system is untenable because the federal government has no power over the price it must pay in Part B, Azar said during a roundtable with reporters on Thursday.

“We are handed a bill and we write a check. That is it,” he said.

Azar added that the system is unsustainable with so many high-cost therapies coming onto the market. Azar estimates the proposal would save Medicare about $17 billion over five years.

The administration aims to put out a regulation outlining this new pricing model in spring 2019, and doesn't need to go through Congress.

Democrats, meanwhile, were highly skeptical of the proposal, and took the occasion to again fault President Trump for attempting to repeal Obamacare.

Rep. Elijah Cummings, D-Md., called the proposal encouraging, but said that “it’s hard to know whether the administration will actually implement this proposal in a way that would lower drug prices for seniors.”

Cummings cited his own encounter with Trump last year during a meeting in the Oval Office. He said that he introduced a bill to give Medicare the power to negotiate directly with drugmakers to lower prices, a reform that Trump repeatedly touted throughout his 2016 campaign.

“Instead, President Trump and congressional Republicans have spent the last two years sabotaging our healthcare system and targeting protections for people with pre-existing conditions,” Cummings said.

Senate Minority Leader Chuck Schumer, D-N.Y., also used the proposal to bash Trump’s attacks on Obamacare.

“It's hard to take the Trump administration and Republicans seriously about reducing health care costs for seniors two weeks before the election when they have repeatedly advocated for and implemented policies that strip away protections for people with pre-existing conditions,” Schumer said in a statement.