The UN has launched a campaign to highlight human trafficking, an issue it says has reached epidemic proportions over the past decade.
Modern-day slavery affects millions of people around the world, the UN Office on Drugs and Crime (UNODC) said.
Its initiative aims to raise awareness of trafficking both among potential victims and those who buy services or products that rely on slave labour.
It comes as the UK marks 200 years since abolition of the slave trade.
The campaign, entitled The Global Initiative to Fight Human Trafficking, brings together a raft of UN agencies and NGOs.
At the launch in London, UNODC Executive Director Antonio Costa said that the types of exploitation varied from place to place.
Many women are forced to work in the sex trade
"In Europe there may be sex-related exploitation while in other parts of the world there may be camel jockeys, children forced to dive looking for pearls or oysters, people beaten like modern slaves, women in quarries," he told Reuters news agency.
He said the campaign aimed to tackle human trafficking "both on the supply side, in making people less vulnerable and more aware, and on the demand side by showing people some of the services they ask for are forms of exploitation".
He also called for greater commitment from countries to legislate against the human trade and to prosecute violators.
According to a report last year by UNODC, countries that were major sources of trafficked persons included Thailand, China, Nigeria, Albania, Bulgaria, Belarus, Moldova and Ukraine.
Thailand, Japan, Israel, Belgium, the Netherlands, Germany, Italy, Turkey and the US were the most common destinations, the report said.
There are no exact statistics on the number of people affected globally.
But according to UNODC, experts believe that some 2.5 million people throughout the world are at any given time the victims of human trafficking.
Many of these are women and young girls forced to work in the sex industry, while others are men forced to work as labourers in dangerous conditions for little or no pay, the UN agency said.