Washington accused Russia and Thailand of failing to tackle human trafficking Monday, while praising progress in Malaysia and Cuba, in a report on a global scourge decried as "modern slavery."
Venezuela, Iran, Libya, Syria, Yemen, North Korea, Zimbabwe and others joined Russia and Thailand at the bottom of an annual ranking compiled by the State Department and announced by Secretary of State John Kerry.
Countries in "Tier 3," the lowest category, are those whose governments do not respect international norms or laws on trafficking and "are not making significant efforts to do so," according to the 382-page report.
But the promotion of Malaysia and Cuba one notch from Tier 3 to the "Tier 2 Watch List" drew allegations that President Barack Obama's administration had politicized the rankings to reward favoured capitals.
Malaysia is among the Pacific Rim nations currently negotiating a sweeping trade accord with Washington, while Cuba and the United States re-established diplomatic ties last week ending decades of hostility.
Asked whether Malaysia's role in trade talks played any factor in hiking the Southeast Asian nation out of Tier 3, undersecretary of state for human rights Sarah Sewall insisted: "No, no, no."
The report said Kuala Lumpur had made "significant efforts" in fighting trafficking.
While Sewall said the May discovery of mass graves believed to be used by Malaysian people-smugglers near the Thai border was a "core concern" for the State Department, it came after the report's review period ended in March.
Several US lawmakers expressed concern over the report.
"They have elevated politics over the most basic principles of human rights," said Senate Democrat Robert Menendez, alleging that the leniency towards Malaysia and Cuba was "a stamp of approval for countries who have failed to take the basic actions to merit this upgrade."
A non-profit coalition of US-based rights groups, the Alliance to End Slavery and Trafficking, was deeply critical, saying Obama's administration "unfairly" upgraded Malaysia by putting trade concerns over human rights.
Russia, where statistics show there are an estimated five million to 12 million foreign workers, has languished in Tier 3 since 2013.
"Many of these migrant workers experienced exploitative labor conditions characteristic of trafficking cases, such as withholding of identity documents, non-payment for services rendered, physical abuse or extremely poor living conditions," the US report stated.
It said Russia lacked a national action plan and funds for trafficking prevention, and "prosecutions remained low compared with the scope of Russia's trafficking problem."
China rose a notch in 2014 to the Tier 2 Watch List, where it remained this year.
Cuba, after 12 years at Tier 3, was upgraded to the Watch List for 2015, with the report citing the island's "sustained law enforcement efforts" in prosecuting and convicting sex traffickers.
- 'Battle against evil' -
Most Western countries, particularly those in Europe and Australia but also Israel, Taiwan and Armenia, are listed in Tier 1, praised for their fight against trafficking and for remaining in compliance with international standards.
According to the International Labour Organization, trafficking in persons represents a $150 billion-a-year industry, including $99 billion for the sex industry alone.
Washington estimates some 20 million people are victims.
"Trafficking in persons is an insult to human dignity and an assault on freedom," Kerry said in the report's introduction as he called for a comprehensive "fight against modern slavery."
In remarks Monday he declared: "It's a battle against money, it's a battle against evil."
US ally Thailand slipped from Tier 2 in 2008 and 2009 to Watch List from 2010 to 2013, then Tier 3 for two years.
Thailand's trafficking problem centers on its extensive sex trade, involving victims from neighboring Myanmar, Laos and Cambodia. There is also reported abuse in commercial fishing.
"Some Thai officials are complicit in trafficking crimes and corruption continues to undermine anti-trafficking efforts," the report said.
Thailand's foreign ministry rejected the ranking, claiming it "did not accurately reflect the significant efforts" made by the current junta to address trafficking.
"Despite the tier ranking, Thailand will continue to do its utmost to overcome the remaining challenges," it added.