The New York representative made the comment on Twitter after paying a visit to Customs and Border Protection (CBP) facilities in southern Texas Monday.
Ocasio-Cortez also said that the CBP agents were "physically and sexually threatening towards me."
"Just left the 1st CBP facility. I see why CBP officers were being so physically & sexually threatening towards me. Officers were keeping women in cells with no water and had told them to drink out of the toilets. This was them on their GOOD behavior in front of members of Congress," read the tweet.
‘Border officers laugh at visiting Congressmen'
The freshman lawmaker further said that the border agents were "laughing in front of" the visiting lawmakers, something their superiors justified by arguing that the officers are "under stress."
"Now I've seen the inside of these facilities. It's not just the kids. It's everyone. People drinking out of toilets, officers laughing in front of members [of] Congress. I brought it up to their superiors. They said ‘officers are under stress and act out sometimes.' No accountability."
The Democratic lawmaker slammed the way the migrants were being treated "like animals."
"It is hard to understate the enormity of the problem. We're talking systemic cruelty w/ a dehumanizing culture that treats them like animals."
‘Psy- war on migrants'
A dozen other House members were on the trip, organized by the Congressional Hispanic Caucus, to visit migrant detention centers in El Paso and Clint, Texas.
Ocasio-Cortez , who was on the way to Clint, called what she had witnessed "horrifying so far."
"Now I'm on my way to Clint, where the Trump admin was denying children toothpaste and soap," she said. "This has been horrifying so far. It is hard to understate the enormity of the problem. We're talking systemic cruelty w/ a dehumanizing culture that treats them like animals."
Treatment of the migrants by the officers was described as "psychological warfare" by one of the victims, according to Ocasio-Cortez.
"After I forced myself into a cell w/ women and began speaking to them, one of them described their treatment at the hands of officers as "psychological warfare" - waking them at odd hours for no reason, calling them wh*res, etc. Tell me what about that is due to a "lack of funding?"