(CNN) - New York Mayor Bill de Blasio said Wednesday that allegations made by US Customs and Border Protection that he had crossed the US-Mexico border illegally last month are "absolutely ridiculous."
De Blasio was one of 20 US mayors who visited the Tornillo facility near El Paso, Texas, in June to get a better understanding of the conditions detained immigrant children are exposed to after being separated from their parents.
De Blasio says he and his team, which included a New York Police Department security detail, were repeatedly denied access to the facility, so they tried to get a better view from the Mexico side.
"The border agents consulted with their supervisor, and they agreed, and they let our cars cross the American border into Mexico at a normal checkpoint. While we were there we were told what the border line was, and we respected it," he said at an unrelated news conference Wednesday in New York. He added that they showed passports at a port of entry to gain legal access.
The comments came in response to a letter, obtained by The Associated Press, from Customs and Border Protection to the New York Police Department claiming de Blasio had violated Mexican and US immigration laws by crossing the border illegally while visiting the area.
The letter states that de Blasio's group ignored CBP orders at the border, according to The Associated Press.
A high-ranking NYPD source confirmed to CNN that the department received a letter. The letter did not call for an arrest, but rather was making the department aware, the source said.
CNN has not seen the contents of the letter and has reached out to CBP for comment.
The mayor called the letter a "distraction," saying, "You can tell when our federal government is doing something that's hurting people. They don't want that to be the focus of attention, so now trying to get the attention off of a policy literally called family separation, they are trying once again to distract."