Pfizer pfe CEO Ian Read has some choice words for Hillary Clinton concerning her new plan to lower drug prices.

“Well, I think in this totality, it will be very negative for innovation,” the pharmaceutical company’s chief executive said during Wells Fargo’s wfc annual Healthcare Conference on Thursday.

Lowering the cost of drugs and avoiding unnecessary price hikes on life-saving treatments is one of the Clinton campaign’s key concerns. In March, she said she was “going after” Valeant vrx , whose price hikes for a number of therapies have drawn widespread condemnation from biopharmaceutical trade groups.

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Clinton already considered letting Medicare negotiate drug prices as one way to reign in costs (among other measures). But after Mylan myl hiked up the price of its EpiPen, the Democratic presidential candidate upped the ante last week with an “aggressive new set of enforcement tools.”

The revised plan now includes potential fines for drug makers making “unjustified” price increases on old drugs, as well as an oversight panel that could import cheaper alternatives from other countries if warranted.

 

While Read does like some of what Clinton has proposed, such as adding a limit to insurance co-pays, “but, you know, you can’t just pick one thing,” he said. “It’s a whole system; you can’t pull out one string without pulling the whole jersey undone.”

Overall, Read thinks Clinton is pushing Americans toward a single-payer system, which he doesn’t believe they want. So what’s the alternative to getting drug prices down?

“I think there are enough institutional forces in the U.S. to ensure that we don’t go down a European route,” he said, acknowledging that more transparency in the health system and extensive conversations between lawmakers, insurers, and the biopharma industry will be key to addressing the problem. He also parroted the common pharma line that the sector’s major problem is in communicating the value of drugs to the public.

Other big pharma CEOs have taken a different approach to the drug pricing controversy. Most recently, Allergan agn chief Brent Saunders pledged a “social contract” with patients that includes responsible drug pricing and limited price hikes.