Demonstrators hold placards as relatives (not pictured) of some of the 43 missing students of Ayotzinapa College Raul Isidro Burgos attend a news conference after a private meeting with Mexico's president, ahead of the first anniversary of the students' disappearance, in Mexico City Sept. 24, 2015. The U.S. State Department has cutoff millions of dollars in aid to Mexico for fighting the drug war. Reuters/Henry Romero

U.S. State Department officials have cut millions of dollars in aid money to Mexico to fight the drug war, the Washington Post reported. Mexico failed to meet human rights goals that are part of funding requirements, prompting the U.S. to shift approximately $5 million to efforts to eradicate coca in Peru from Mexico's fight against drug cartels.

“From time to time, countries are unable to meet the reporting criteria as required by Congress,” the State Department said in a statement to the Washington Post Sunday. “This year, we were unable to certify that Mexico fully meets the criteria.”

Experts say the funding reduction shows how frustrated the U.S. has become over the human rights situation in Mexico. U.S. officials did not publicly announce the funding cut, however, highlighting how the two governments will continue to work together. The $5 million cut was small when compared with the total $148 million in U.S. government funding allocated for the year toward stopping Mexican drug cartels.

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The U.S. has given Mexico $2.3 billion since 2008 through the Merida Initiative to help the government fight drug trafficking. The Mexican government has used the funds to buy equipment and train officers. Of the total funding, 15 percent was dedicated to police and military officers and was contingent on Mexico making progress on human rights protection. U.S. government officials must write to Congress explaining how Mexico has made progress, but this year officials decided not to write the report.

The financial pullback coincides with several high profile cases involving the police and security forces in Mexico. In September 2014, 43 students disappeared in the southern state of Guerrero after a police shootout. The case highlighted links among police, politicians and organized crime. At least 129 bodies were found in Guerrero in secret graves in the last year while the student case remains unresolved.

Mexican officials were embarrassed in July when drug kingpin Joaquin "El Chapo" Guzman escaped from prison using an underground tunnel. Authorities have said in recent days they had narrowed in on his location after he had evaded an attempt to capture him last week.