(CNN) -- The annual Trafficking in Persons Report -- the world's most comprehensive resource of governmental anti-human trafficking efforts -- was published Tuesday by the U.S. State Department.
It identifies countries that the U.S. says meet minimum standards of anti-trafficking efforts, countries working towards them and countries that appear to be doing little to stop trafficking.
The report is compiled with the help of U.S. embassies, non-governmental organizations, aid groups and individuals around the world.
Secretary of State Hillary Clinton said: "Ultimately, this report reminds us of the human cost of this crime. Traffickers prey on the hopes and dreams of those seeking a better life and our goal should be to put those hopes and dreams back within reach, whether it's getting a good job to send money home, to support a family, trying to get an education for one's self or for one's children or simply pursuing new opportunities that might lead to a better life.
"We need to ensure that all survivors have that opportunity to move past what they endured and to make the most of their potential."
Each country is put into one of four grades - Tier 1, Tier 2, Tier Two Watch and Tier Three. Tier 1 is achieved by reaching minimum anti-trafficking standards and it does not highlight countries doing above and beyond the minimum.
For the first time in 11 years Myanmar has been promoted from Tier 3 to Tier 2 Watch. The report says Myanmar is primarily a source country for trafficking to other Asia countries, but there are still significant domestic trafficking problems and children can be conscripted into the national army.
It recommends Myanmar demobilizes child soldiers and focuses more attention on domestic sex trafficking of women and children.
The Czech Republic -the only country last year to slip out of the top-ranked countries - regained its Tier 1 status having introduced a series of anti-trafficking laws and securing successful trafficking convictions.
Iceland, Israel and Nicaragua were also promoted to Tier 1.
Portugal, however, was downgraded to Tier 2 because while new laws and initiatives were introduced, there was no evidence it was leading to prison sentences for the majority of convicted traffickers.
Nigeria and Bosnia-Herzegovina also fell out of the top-ranked countries.
Kenya was downgraded to Tier 2 Watch because it did not show evidence of increasing efforts to combat human trafficking.
Syria -- with its ongoing violent conflict -- was the only country relegated into Tier 3. The report said the lack of security made it difficult to check anti-trafficking measures.
Before the unrest Syria was primarily a destination country for trafficked women and children. The report found the unrest had put more people at risk from traffickers, particularly vulnerable segments of the population like Iraqi refugees.
The Tip Report's ranking system is largely dependent on the amount of work being done by the national government rather than non-government or international organizations.
It includes counting known cases of human trafficking in more than 175 countries, whether for commercial sex, bonded labor, child labor, involuntary domestic servitude or child soldiers. And it tracks new legislation, prosecutions and convictions.
Tier 1 ranking indicates a government has acknowledged the existence of human trafficking, has made efforts to address the problem, and meets minimum standards.
Tier 2 is countries whose governments do not fully comply with minimum standards but are making significant efforts to bring themselves into compliance.
Tier 2 watch is countries where governments do not fully meet minimum standards, and although they may be making significant efforts the country has a particularly large number of victims, or is not providing evidence of its efforts.
Tier 3 is countries that do not fully comply with minimum standards and are not making significant efforts to do so. Tier 3 countries face the possibility of US sanctions because of their poor human trafficking record.