Updated

The diplomat heading U.S. efforts to combat drug trafficking internationally is hailing a pending U.N. move to control substances used to make a deadly synthetic drug, but acknowledges it will not put an immediate dent in illegal trafficking.

William Brownfield says the move to globally track the legal movement of fentanyl and substances used to make the drugs is an important step to reduce illegal use.

But he told The Associated Press Tuesday that it is only one step in reducing dependency or addiction on the drug that may have contributed to 33,000 U.S. deaths in 2015.

Brownfield spoke outside a meeting of the U.N. Commission of Narcotic Drugs. It is expected to put fenatyl and its precursors on a list of controlled substances, allowing for better monitoring of global movements.