Kerry made the public announcement of more financial assistance to Ukraine at a news conference during his visit to Kiev.
US Congress said in January it would disburse a billion-dollar loan guarantee to Ukraine if it followed through on its reform plans.
Washington has pledged financial assistance several times to the war-torn country, allegedly to bolster its defense capabilities amid tensions in its southeast.
The promise of more funds comes amid reports that Washington is also considering supplying lethal aid to Kiev, including Javelin anti-tank missiles, arms and ammunition.
Kiev has been particularly persistent in its requests for US arms supplies during and in the months after Ukrainian President Petro Poroshenko's visit to Washington last year. The US administration has so far objected to providing Ukraine with lethal aid, though the White House has previously indicated its willingness to reassess that position.
