The U.S. State Department has declared that it will cut $5 million from its drug aid to Mexico due to the latter's failure to address human rights issues.

The cut is a small part of the U.S.' roughly $2.3 billion aid package to Mexico through the Merida Initiative, a major American program to combat drug cartels, The Washington Post wrote. It has been in effect since 2008 for equipment such as helicopters and border sensors, as well as providing training programs for thousands of Mexican officials. The aid is also for the protection of human rights, including enforcing rules against torture and prosecuting people believed to be involved in disappearances.

A statement from the State Department said that there are times when "countries are unable to meet the reporting criteria as required by Congress," and that this year, they are "unable to certify that Mexico fully meets the criteria," The Washington Post further reported. The portion intended for Mexico is now going to Peru's coca abolition.

Withholding a portion of the anti-drug aid is a sign of the U.S.' growing frustration over Mexico's military and police, according to the news outlet. One of the most controversial issues plaguing Mexico is the 2014 disappearance of 43 students in the state of Guerrero.

"It's a big decision for them to have made," said Maureen Meyer, a Mexico expert at the Washington Office on Latin America, as quoted by The Washington Post. "I think they basically decided we cannot honestly or in good faith say there's been enough progress made in Mexico. It shows how concerned the U.S. is about the human rights situation in the country."

This is not the first time that the Congress refused to give Merida money to Mexico because of human rights problems, but it eventually would release the funds once the country addressed the issues, The Washington Post wrote. Mexico took action in the past by passing human rights legislation and putting limits to the jurisdiction of military courts.

The U.S. made the funding decision peacefully because Mexico is still an ally in battling the drug war and is a significant diplomatic partner. The Mexican Foreign Ministry, meanwhile, said that the cut in aid is "an obligation imposed by the U.S. Congress on the government. It is not an obligation Mexico has to meet," the news outlet noted.

The State Department's most recent annual report for 2014 noted about the several allegations directed at Mexican authorities who are said to have "committed arbitrary or unlawful killings, often with impunity." Security forces are also accused of involvement in torture and disappearances.