Since the tradition began in 1954, the title of goodwill ambassador for United Nations’ agencies has usually been appended to names that might have been borrowed from the credits for a film festival: Danny Kaye, Audrey Hepburn, Mia Farrow, Susan Sarandon and, lately, Angelina Jolie and George Clooney.

But on Tuesday Simone Monasebian, the New York chief of the United Nations Office on Drugs and Crime, introduced the next ambassador to be named for her office, a man well known in certain circles but not often followed by paparazzi: Ross Bleckner, the painter, who will be the first fine artist named to the ceremonial post.

Earlier this year Mr. Bleckner, whose mostly abstract work came to prominence in the 1980s and who has long been involved in AIDS-related causes, went on an official mission to the Gulu district of northern Uganda. Gulu has been terrorized for many years by the rebel force known as the Lord’s Resistance Army, which has abducted and conscripted thousands of children, forcing boys and girls to become killers and sex slaves.

Using thousands of dollars’ worth of paint, brushes and paper shipped from New York Central Art Supply in the East Village, Mr. Bleckner, 59, worked with a group of 25 children — former abductees and ex-soldiers — for more than a week at a Roman Catholic aid center. The children made 200 paintings that will be sold at a benefit at the United Nations headquarters next month at which Mr. Bleckner will be appointed goodwill ambassador. Several of the luminous paintings are now on view in the front window of the clothing store Moschino in the meatpacking district, whose company is providing money to support the Gulu project.

“One of the things we realized about a fine artist, a painter, in this role is that the work that emerges from it really needs no translation, no dubbing like a documentary or music — it’s immediately accessible to anyone who sees it,” said Ms. Monasebian, whose office estimates that human trafficking generates $32 billion a year in profits, third only to drug and arms trafficking.

Mr. Bleckner said that when United Nations officials first approached him, they asked him whether he thought art could perform a useful role in drawing attention to the plague of human trafficking, which they said still receives too little attention, despite the widespread use of children in many conflicts in Africa.

“And I said to them that if art can’t perform a role like that, then it has no role at all,” he said on Tuesday.

The former abductees, many of them orphans, ranging in age from 11 to 19, had experienced horrific trauma, and some had been forced to kill or maim other children or adults before they escaped from, or were released by, the rebel movement.

He said that after several days of teaching them rudimentary painting and drawing skills, many began to open up to him and to create work that powerfully expressed their experiences. (Mr. Bleckner said one haunting portrait made as part of the project is thought to be that of a henchman of Joseph Kony, the infamous commander of the Lord’s Resistance Army. Mr. Kony is wanted for crimes against humanity by the International Criminal Court, whose Trust Fund for Victims helped identify the children who participated in the painting project.)

Mr. Bleckner said that he planned to return to the area early next year to enlarge the painting project and that — in his role as ambassador — he hoped to enlist many more artists to become involved in efforts to fight child enslavement and trafficking.

“What this mission accomplished is what I call microcreativity,” Mr. Bleckner wrote in a catalog of the children’s work. “It is a personal interaction which gives someone the tools to create something that they can be proud of, and which can help them on the arduous path to restoring their dignity and sense of self-worth.”