The Vienna-based UN Office on Drugs and Crime (UNODC) cited a sharp increase in cocaine and opium production profiting criminal gangs and terror groups in its annual report published Thursday.
"There is much work to be done to confront the many harms inflicted by drugs, to health, development, peace and security, in all regions of the world," said Yury Fedotov, the head of the agency.
Its report describes a coca plant boom in Colombia that appeared to have resulted in increased cocaine deliveries to Europe and North America.
A peace deal between the Colombian government and rebels foresees farmers switching to legal crops, but rebel groups and drug traffickers were still involved in Colombia's coca business, the agency alleged.
Global production of opium, the precursor for heroin, had jumped 30 percent in 2016 - after previous weak yields - because of a sustained Afghan poppy harvest.
The business was controlled by Taliban insurgents, it said, making between $150 million to $200 million (135 million and 179 million euros) a year from taxing farmers and smugglers.
Africa had seen "some of the sharpest increases in heroin use" of any world region because users lived along the so-called southern trafficking route that connects Afghanistan and Europe, the agency said.
It cited rising numbers of users in Kenya, Tanzania, Mozambique, Zambia, Nigeria and Ivory Coast.
Cocaine seizures in Asian countries had increased by 40 percent in 2015.
Increasing flows of Mexican heroin into the United States had exacerbated America's epidemic of synthetic opium-type drugs. Some 33,000 people had died from opioid overdoses in the US in 2015.
183 million cannabis users
Large cannabis seizures had taken place in North and South America, as well as Northern Africa. In Europe, the biggest producers were in the Netherlands and Albania.
Summarizing usage worldwide, the UNODC estimated that 183 million people use cannabis.
Amphetamine users totaled 37 million, those of opium-type drugs 35 million, the synthetic narcotic ecstasy 22 million and cocaine 17 million.
Organized crime gangs constantly changed their practices and were using new technologies such as the "darknet" to traffic drugs, said the UNODC.
Fedotov said that while "the international community is equipped to respond swiftly... there remains an enormous need for capacity-building and technical assistance, and funding continues to fall short of political commitments."
ipj/rc (AFP, dpa, AP)