Human rights advocates on Monday accused the State Department of making political calculations when it upgraded Malaysia and Cuba in the annual ranking of where countries stand in combating human trafficking.

Both countries were removed from the list of the worst offenders in the Trafficking in Persons Report issued Monday. Last year, they were Tier 3 countries, a category reserved for nations that don’t meet minimum standards to fight modern-day slavery, and aren’t doing anything to improve.

This year, 23 nations got that designation. But Cuba and Malaysia were listed among 44 countries a notch up, on a Tier 2 Watch list comprised of nations that don’t meet standards but are working to better the situation.

The timing raised suspicions that politics played a role.

The United States and Cuba last week reestablished diplomatic ties for the first time in 54 years. Cuba also was removed from the State Department’s list of state sponsors of terrorism earlier this year.

Malaysia, where mass graves were unearthed in May at remote camps run by migrant smugglers near the Thai border, is one of 12 countries in the Trans-Pacific Partnership, one of the Obama administration’s key economic ambitions expected to be finalized this week in Hawaii.

“It really looks for the first time like the report has been used to further a number of political aims, which is a terrible development,” said Sarah Margon, the Washington director of Human Rights Watch. “It undermines the report’s credibility.”

Sarah Sewall, undersecretary of state for Civilian Security, Democracy and Human Rights, said the upgrade of Malaysia was justified because the government is working harder to crack down on traffickers. It has proposed legislation to strengthen its anti-trafficking laws, and increased trafficking investigations and prosecutions.

“We remain concerned that low numbers of trafficking convictions in Malaysia is disproportionate to the scale of Malaysia’s human trafficking problem, and we also remain concerned with the restrictions on victims detained in government facilities and inadequate efforts to address pervasive passport retention by employers,” she told reporters.

Sen. Robert Menendez (D-N.J.), among 19 senators and 160 House lawmakers who wrote to Secretary of State John F. Kerry urging that he keep Malaysia a Tier 3 country, said he would challenge the upgrades of both Malaysia and Cuba through hearings, legislation and investigations.

Malaysia and Cuba were among 18 countries that were upgraded in this year’s report, balanced by 18 that fell a notch. Cuba was upgraded because the report said it is working to address sex trafficking and providing services to victims.

In Malaysia, the report estimated, there are 2 million undocumented workers who migrated there for economic opportunity only to be plunged into forced labor or debt bondage.

Some human rights advocates say Malaysia’s progress is minimal at best. In 2014, only three traffickers for forced labor were convicted, down from nine the previous year.

“Malaysia has done virtually nothing on human trafficking,” said David Abramowitz, head of policy and government relations for Humanity United, which sponsors the Alliance to End Slavery and Trafficking. “I believe the upgrade of Malaysia is unwarranted and suggests human trafficking victims were sold out for trade, politics and regional concerns.”

The 384-page Trafficking in Persons Report is a window on heartbreaking human bondage in the 21st century. More than 20 million people around the world are thought to be enslaved as laborers for industries that include prostitution, domestic help, construction, fishing and mining.

In Belize, women and girls are sold into the sex trade by relatives. In Thailand, migrants have their documents taken away and are forced onto fishing boats that remain at sea for years at a time. In Ghana, boys are put to work mining gold and girls are forced into domestic servitude to atone for the sins of a relative.

Being listed among the worst offenders in Tier 3 can mean sanctions and a cutoff of U.S. aid. President Obama has 90 days after the report is delivered to decide whether to grant a waiver from funding restrictions.

During an event at the State Department on Monday, Kerry said the report’s function is “not to scold and it’s not to name and shame. It is to enlighten and to energize and, most importantly, to empower people.”