By Esmeralda Lopez and Samir Goswami, Special to CNN

Editor’s note: Esmeralda Lopez, JD, serves as Amnesty International USA’s Mexico Country Specialist. Samir Goswami is Director of Amnesty International USA’s Individuals and Communities at Risk Program. The views expressed are their own.

If 26 American women filed complaints against authorities for committing horrific sexual assaults, and those police officers remained free and employed seven years later, you would rightly expect that the local political ramifications would be dire, and the official government response would be strong.

But in San Salvador Atenco in the State of Mexico, there is only sickening indignation and impunity.

On May 4, 2006, Bárbara Italia Méndez was one of 47 women arrested during two days of protests in San Salvador Atenco. Like 26 others who filed complaints, she was allegedly subjected to physical, psychological and sexual violence at the hands of the police. Allegedly beaten and detained without explanation, she was then reportedly forced to remove her clothing and lie on top of other detainees while members of the state police beat, threatened, sexually assaulted and raped her as other officers looked on and cheered.

She is still waiting for justice.

This week, almost seven years to the day after the alleged horrific crimes were committed against Bárbara and so many others, President Barack Obama will visit Mexican President Enrique Peña Nieto on a “goodwill journey.” We hope he will have the courage to tell Peña Nieto, who was the State of Mexico’s governor in May 2006, that he should promote the rule of law and justice in his country, especially with regard to widespread violence against women.

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Bárbara and the other women assaulted in San Salvador Atenco advocated for themselves when the local authorities would not respond. In the beginning, the State Public Prosecutor’s Office repeatedly dismissed their complaints and, after years of seeking justice in Mexico, they took their case to the Inter-American Commission on Human Rights. Today, the in-country investigation remains stalled, and the Mexican authorities have not responded convincingly to the case.

At the time of the protests and alleged assaults, Peña Nieto was criticized for his handling of the situation, and a Mexico National Commission on Human Rights investigation blamed him and then-Secretary of Public Safety Eduardo Medina Mora for the human rights violations and the impunity granted to its perpetrators. Six years later, Peña Nieto is president of Mexico and Mora is the Mexican ambassador to the United States. There can be no clearer example of impunity.

Verbally and publicly, Peña Nieto has assumed responsibility for what took place in San Salvador Atenco on May 3 and 4, 2006, and declared his commitment to promoting human rights. Yet, he has taken no action. And, even as the president fails to act, statistics underscore how violence against women in Mexico continues unabated. A U.N. report has estimated that Mexico suffers 120,000 rapes a year. Yet despite this stomach-turning statistic, when it comes to combating violence against women and upholding sexual and reproductive rights, Mexico’s leaders appear indifferent.

The time is ripe for the United States to speak up. In addition to the uncanny timing of President Obama’s visit, the United States Agency for International Development is preparing to launch its Mexico Promoting Justice Project. With $100 million designated to promote rule of law that will support police, court and justice system reforms, how can the U.S. remain silent?

Human rights activists worldwide have joined Bárbara Italia Méndez and the other brave women of Atenco in their call for justice. Now, President Obama, along with other leaders, must pressure Mexican officials to address the impunity granted to those who commit acts of gender-based violence, and ensure that women’s human rights are respected. He must seize this moment and urge President Peña Nieto to finally right this historic wrong.

It is time for Mexican authorities to take action on the issue of human rights in their country. It is time for President Peña Nieto to step up and back up his verbal commitment to the rule of law with action. It is time for Bárbara Italia Méndez, and so many others, to have justice.