UNITED NATIONS (Reuters) - Russia has delayed a western proposal for a U.N. Security Council committee to blacklist six accused leaders of human trafficking and migrant smuggling networks in Libya, asking for more information on the value and efficiency of the move.

The Netherlands, backed by France, Germany, Britain and the United States, asked the 15-member council’s Libya sanctions committee to impose a global asset freeze and travel ban on six people. But Russia put a so-called “technical hold” on the request earlier this month. The committee operates by consensus.

“We hope that the designating committee members will share with others at least some of “extensive evidence” from “reliable sources” confirming the involvement of the six individuals in the illicit activities they are accused of,” the Russian U.N. mission said in a letter to the committee, seen by Reuters.

The Russian U.N. mission wanted to know “how the problem can be solved without dealing with criminals from countries of origin and countries of destination,” noting the designation proposal indicated that “networks stretch to many European countries and the United States.”

The proposal to impose targeted sanctions on the six people comes after a video, appearing to show African migrants sold as slaves, sparked global outrage late last year.

U.S. Ambassador to the United Nations Nikki Haley told a council meeting on Libya on Monday that “failing to move forward with the designations would be a travesty in the face of so much global outrage over these abuses.”

“The evidence showing the involvement of the six people is clear,” Haley said.

Under a sanctions regime set up in 2011, the Security Council is able to impose a global asset freeze and travel ban on “individuals and entities involved in or complicit in ordering, controlling, or otherwise directing, the commission of serious human rights abuses against persons in Libya.”

“It is time our words are turned into action,” deputy Netherlands U.N. Ambassador, Lise Gregoire Van Haaren, told the council on Monday.

Libya descended into chaos after a NATO-backed uprising in 2011 led to the overthrow and killing of leader Muammar Gaddafi, with two competing governments backed by militias scrambling for control of the oil-producing country. Islamic State militants also gained a foothold in the North African state.

People smugglers operating with impunity in Libya have sent hundreds of thousands of migrants by sea to Europe, mainly Italy, since 2014. Thousands have died during these voyages.