The head of the Centers for Disease Control and Prevention stressed Tuesday that it was necessary to remove the stigma around addiction in order to confront the opioid crisis.

"Addiction is a medical condition, not a moral failing," said CDC director Robert Redfield.

The comments from Redfield came as his agency released data earlier in the day showing a slight dip in opioid overdose deaths for six months in a row. The data show that deaths have decreased by 2.8 percent since their peak, but it's not yet clear whether this is a reversal in the crisis that will continue, or a temporary drop.

The opioid crisis claimed more than 40,000 lives in 2017. Redfield did not make predictions as to whether the dip reported Tuesday represented the beginning of a shift in the opioid crisis, but stressed that it continued to be a priority for the Trump administration.

[Related: FDA considers requiring co-prescribing overdose antidote to go along with opioids]

President Trump is expected to sign a bill into law on Wednesday that takes a wide-ranging approach to the epidemic through more medical research, law enforcement tools, and access to treatment for addiction.

Redfield, who was a leading researcher on HIV/AIDS before taking the helm at the CDC, drew parallels between the HIV/AIDS epidemic during the 1980s and the addiction outbreak in the U.S. today. He discouraged members of the audience from using terms like "addict."

"I think these are very stigmatizing terms," he said.

The comments, part of a Milken Institute event in Washington, D.C., drew applause from the audience. Redfield shared that he has a son who has an opioid addiction, who has been in recovery for two years.

"Society needs to come together and support recovery [from drug addiction] as the rule, not the exception," he said.