”Gun laws in the United States don’t make much sense," he said during a speech at the VTEX Day digital e-commerce event in Sao Paulo, Brazil on Thursday, Presstv Reported.
“Anybody can buy any weapon, any time without much, if any, regulation," he said, adding, "They buy it over the internet. They can buy machine guns.”
Obama recalled the 2012 Sandy Hook Elementary School shooting that left 26 dead, including 20 young children in Newtown, Conn.
He said the day that he had to comfort the parents of the children killed in the mass shooting was his worst day in office.
“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. My daughters were only a little bit older than these young children that have been shot, and I had to go and comfort the parents," Obama told the crowd during his appearance.
The Sandy Hook tragedy has been followed by a number of other deadly mass shooting incidents which have sparked calls for gun reform among people, activists and politicians.
A US government report earlier this year showed the number of mass shootings on US school campuses have risen steeply in recent years and have become much deadlier .
A Reuters/Ipsos poll indicated widespread disappointment among Americans with current US gun laws.
According to the poll released in February, 69 percent of US population, including 85 percent of Democrats and 57 percent of Republicans, wanted gun laws to change.