President López Obrador confirmed Tuesday that he would file a lawsuit against a United States-based lawyer for allegedly slandering him at the New York trial of former federal security minister Genaro García Luna.

Defense lawyer César de Castro last week asked prosecution witness and former Sinaloa Cartel member Jesús “El Rey” Zambada whether he recalled telling U.S. authorities in 2013 that he delivered US $7 million to a Mexico City official to fund the 2006 presidential campaign of López Obrador, who was mayor of the capital between 2000 and 2005.

Zambada, brother of Sinaloa Cartel leader Ismael “El Mayo” Zambada, denied ever saying such a thing.

López Obrador said last Thursday that he was considering filing a lawsuit against de Castro for “moral damage” and that he could seek $7 million in compensation and give any payout to families of victims of the militarized war on drug cartels launched by Felipe Calderón shortly after he was sworn in as president in 2006.

On Tuesday he said he had decided to file the suit but was still “doing some research on how the procedure works.”

López Obrador added that he was waiting for advisers to inform him where to initiate the legal action. “In a few days we’ll know, I’ll tell you here,” he said.

His remarks came just hours before a jury found García Luna guilty of collaborating with the Sinaloa Cartel in its drug trafficking activities.

López Obrador said Wednesday that the conviction was proof of the “decadence” of previous governments. However, the verdict against García Luna “isn’t a judgement against Mexico, let’s make that clear,” the president said.

“I would even say that it helps to continue cleaning up corruption in Mexico. … Of course more needs to be done, it’s the beginning, but it’s a good contribution,” he added.

With reports from El Financiero, Infobae, Publimetro and Milenio