June 27 (UPI) -- The U.S. State Department declared China as among the world's worst offenders in human trafficking and forced labor, joining a 23-nation list that includes Iran, North Korea, Syria and Russia.
The designation was formally announced Tuesday by Secretary of State Rex Tillerson on Tuesday in releasing the 2017 Trafficking in Persons Report. Ivanka Trump, the president's daughter and senior adviser, also attended the ceremony.
The department's annual assessment of human trafficking includes more than 180 countries and has four categories.
"Human trafficking is one of the most tragic human rights issues of our time," Tillerson said in an statement accompanying the report. "It splinters families, distorts global markets, undermines the rule of law, and spurs other transnational criminal activity. It threatens public safety and national security.
"But worst of all, the crime robs human beings of their freedom and their dignity. That's why we must pursue an end to the scourge of human trafficking."
China was listed as a Tier 3 offender for human trafficking and forced labor -- the lowest ranking -- one year after being on a Tier 2 "watch list" deserving special scrutiny.
China, the report said, "does not fully meet the minimum standards for the elimination of trafficking and is not making significant efforts to do so; therefore, China was downgraded to Tier 3"
In the past, Tier 3 countries can be penalized with sanctions barring them from participating in cultural exchanges with the United States.
If a nation is on the Tier 2 Watch List for two years, it automatically drops to Tier 3. China was granted a waiver last year.
The report listed human trafficking that occurs in China, including forced labor, forced begging, sex trafficking and exploitation, and the trafficking of women, men and children from other countries into China.
The report said China "took some steps to address trafficking," but noted it needs to do better.
Beijing says it has abolished state-sponsored forced labor, but gaps in the law allow traffickers to operate.
Before the move was released, Chinese Foreign Ministry spokesman Lu Kang said China strongly opposes the United States "speaking irresponsibly," and wants to strengthen cooperation in fighting human trafficking.
President Donald Trump has been positive toward Beijing on trade and currency while seeking President Xi Jinping's cooperation in pressuring North Korea on its nuclear program. But the president tweeted last week that Xi and China's efforts to help with North Korea have "not worked out." The two leaders met in Florida in April.
According to the International Labor Organization, an estimated 21 million adults and children are exploited by human traffickers worldwide.
Four other counties were downgraded to Tier 3: Democratic Republic of the Congo, Republic of Congo, Mali and Guinea.
Three other nations are listed as a "special case": Libya, Somalia, Yemen -- among the six nations on Trump's 90-day travel ban, partially allowed by the U.S. Supreme Court on Monday. The other nations with bans are Iran, Sudan and Syria -- all listed as Tier 3
Guyana and Luxembourg rose from Tier 2 to Tier 1 and nine rose from the Tier 3 to the Tier 2 watch list, including Myanmar, formerly known as Burma, and Haiti.
Ukraine and Qatar moved from the Tier 2 watch list to Tier 2.