Kerry expressed optimism that the aid would help boost pro-Western forces within the opposition as well as increase pressure on Assad to step down.
Kerry said the Syrian strongman, who has launched a bloody crackdown on the uprising, was “out of time and must be out of power.”
"For more than a year, the United States and our partners have called on Assad to heed the voice of the Syrian people and to halt his war machine," he said. "Instead, what we have seen is his brutality increase.
"The United States' decision to take further steps now is the result of the brutality of superior armed force propped up by foreign fighters from Iran and Hezbollah," Kerry added.
U.S. officials said they would vet which opposition forces received aid to insure that assistance was not provided to extremist elements, according to reports.
The administration has been reluctant to provide direct assistance in the past, amid fears that it could fall into the hands of Islamist insurgents.
But the White House has faced increasing pressure in recent weeks to do more to help rebel groups in the 2-year struggle, which has already claimed 70,000 lives. The move stops short of providing weapons to the Syrian forces, a move many GOP hawks led by Sens. John McCain (Ariz.) and Lindsey Graham (S.C.) are pushing for.
Sen. Marco Rubio (R-Fla.) in a foreign policy address Wednesday also pressed for the administration to begin sending ammunition to the Syrian fighters. And the top Democrat on the House Foreign Affairs Committee, Rep. Eliot Engel (D-N.Y.), is introducing legislation to arm the opposition.