(CNN) The United States on Thursday added Saudi Arabia and Cuba to its list of worst offenders on human trafficking, a designation that could make them "subject to certain restrictions on assistance."

The two nations were added to the lowest tier in the State Department's 2019 Trafficking in Persons (TIP) Report. Russia, China, Venezuela, Iran, North Korea, Syria, South Sudan, the Democratic Republic of Congo and Myanmar are among the 21 Tier 3 countries.

The countries listed in this tier do "not fully meet the minimum standards for the elimination of trafficking and (are) not making any efforts to do so," according to the report.

"Some of these governments allow human traffickers to run rampant, and other governments are human traffickers themselves," Secretary of State Mike Pompeo noted in remarks at the report's release Thursday morning.

Tier 3 countries may face cuts to "non-humanitarian, non-trade related foreign assistance" and "for government official or employee participation in educational and cultural exchange programs," the report states.

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