By Nima Elbagir, Raja Razek and James Masters, CNN

(CNN) -- Dutch Foreign Minister Stef Blok told CNN on Monday he will press the UN Security Council to expand the list of those who should face international sanctions for human trafficking.

Six men who allegedly made fortunes buying and selling vulnerable migrants were hit by UN sanctions in June in an unprecedented response to the international slave trade, following CNN reporting in Libya.

The move was followed by the United States, which issued sanctions against the six men.

Blok said Monday he would ask the United Nations for further action against countries and individuals involved in trafficking. He spoke with CNN in New York, where the UN Security Council is due to meet Wednesday,

"The people involved very well realize that they are under scrutiny now, and their business model can't work the way it used to work ... and that they are on our target list," he said.

"It is a horrible story," he said. "All the members of the Security Council realized they couldn't stand aside when those terrible things are happening, and they did agree on sanctions."

Each year, tens of thousands of people pour into Libya -- the final transit stop before a short but dangerous sea voyage across the Mediterranean to Europe.

For those involved in the smuggling and trafficking networks, it has been a lucrative business, according to the European Migrant Smuggling Center (EMSC).

In 2015, migrant smuggling networks made at least $5.5 billion trafficking people bound for Europe, according to a 2017 EMSC report. There was a sharp decline in 2016, according to the same report.

Last year, CNN reporters went undercover at a slave market in Libya to document the violation of human rights and inhumane treatment that desperate migrants have suffered.

The CNN evidence was handed over to the Libyan authorities, who immediately launched investigations into networks operating in the region.

The footage also sparked international condemnation and protests around the world.