The US State Department said between 600,000 and 800,000 people are trafficked across international borders every year and 80 percent of those are women.
A survey by the UN found that human trafficking cases have reached a record-high in recent years.
The survey - Global Report On Trafficking In Persons - conducted by the United Nations Office on Drugs and Crime (UNODC) for 2016 has noted that armed conflict and displacement are major drivers of human trafficking.
The UNODC’s report also said that while countries are finding more victims - mostly women trafficked for sex - and convicting more traffickers, the total number of convictions remained very low in many nations - especially in Africa and the Middle East.
And around 17,000 people are trafficked in the US every year.
Alexi Noelle met with victims of sex trafficking in New York to discuss the problem in the United States.
About 600 trafficking routes globally have been identified - in every region of the world - an increase of almost a quarter between 2007 and 2014, according to the latest UN statistics.
About 40 million people worldwide are living as slaves - trapped in forced labor or forced marriages - according to a landmark estimate by Australian rights group the Walk Free Foundation and the UN International Labor Organization (ILO).
Yet campaigners say more and better data is needed to track progress in pursuit of a UN target of ending modern slavery and human trafficking by 2030 as many victims around the world - including child soldiers - are going uncounted.