"Britain's position is that at the moment we do not think that supplying arms is the right thing to do but obviously if the situation on the ground changes we'll keep that position under review," Hammond told Sky News.
On Saturday, the UK foreign secretary announced that his country would not be supplying arms to Ukraine, stressing that London was "focused on a diplomatic track" in addressing the conflict in eastern Ukraine.
Hammond's words followed Germany's Chancellor Angela Merkel's statement that her country would not be sending lethal weapons to Ukraine. France and Finland ruled out the supplies of weaponry as well, calling for a diplomatic solution.
Several politicians, including US Senator John McCain, disagreed with European leaders' position on the matter, calling for the provision of lethal aid to Kiev.
Attempts to find a peaceful solution to the hostilities in southeastern Ukraine have so far failed. Despite the ceasefire deal signed in September 2014, fighting between Kiev forces and independence supporters has surged in recent weeks.