President-Elect Donald Trump, who has pledged to solve the nation’s opioid crisis, faces significant hurdles in achieving that campaign promise, according to The Wall Street Journal.

Much of the work of preventing drug overdose deaths is done at the local level, the article notes. Newer and deadlier versions of opioids are continually appearing. In addition, complex regulatory changes are often needed to rework federal drug policies.

Trump has vowed to dismantle parts of the Affordable Care Act, which requires millions of subsidized health plans to cover treatment for substance use and mental health disorders.

He has vowed to prosecute illegal drug traffickers more aggressively, and to close shipping loopholes that he says allow the Chinese to mail synthetic fentanyl into the country. He also called for reducing the amounts of legal prescription opioids that can be manufactured and sold in the United States, and increasing access to naloxone for first responders to medical emergencies.