US human rights advocates have 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, the Washington Post reported on Tuesday.

Both countries were removed from the list of the worst offenders in the Trafficking in Persons Report issued on 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.

Sen. Robert Menendez, 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.

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.