Former President Barack Obama spoke out against the availability of firearms in the United States during a speech in Brazil on Thursday, The Daily Caller reports.

“The most difficult day that I’ve had was the day that there was a shooting in a school where 20 small children were shot,” the former commander in chief said in an interview at VTEX DAY, a conference being held in Sao Paulo, when asked what was his hardest day in office.

“Some of you may be aware, our gun laws in the United States don’t make much sense,” he added. “Anybody can buy any weapon, any time without much, if any, regulation. They buy it over the internet. They can buy machine guns.”

Brazil’s newly elected President Jair Bolsonaro issued a temporary decree in January increasing the people’s ability to purchase and carry guns.

“Having to speak to parents who had lost a child just a day or two after it had happened, and not being able to assure them that…that would change, that we would fix this. I couldn’t bring their children back, but I couldn’t even promise them that we would change the laws so this didn’t happen to somebody’s children,” Obama said.

“That was the day that was emotionally most difficult for me,” he added.