Kratom, a plant that grows in Southeast Asia, has been used for centuries in parts of Southeast Asia to relieve pain, nausea and vomiting.
Its active ingredient, mitragynine, is often used as a treatment for cancer and as a sedative in patients with seizures and other conditions.
A growing number of countries, including the United States, have legalized the drug for medical use.
It is legal to grow kratom in some states, but many states restrict where people can grow it and sell it.
Some states allow only one plant to grow in a given area.
A 2015 study from the University of Maryland Medical Center found that about 40 percent of patients using kratom experienced negative side effects and a significant increase in the number of people taking the drug.
It’s also not a recommended treatment for most other ailments, including depression and anxiety.
But there is growing concern that it can cause problems, including addiction.
It has also been linked to violence, including a 2014 incident in South Korea when a man died of a heart attack after using the drug to treat depression.
A survey of more than 500 people who use kratom found that more than half had used the drug at least once in their lives, and about half had tried to get hooked on it.
A DEA spokesman, Steve Anderson, said the agency’s goal is to reduce the use of the drug by as much as 80 percent over the next year.
The agency has increased efforts to educate the public about the risks of kratom and has begun to work with health departments and public health officials to develop programs that target the most vulnerable groups.
But the DEA said that it does not have the resources or the authority to enforce new rules or regulations.
Associated Press writers Kim Yoo-sung in Seoul and Kim Yong-seok in Seoul contributed to this report.