David Grimason has been campaigning for tighter controls on the trade of weapons since his two-year-old son Alistair was killed during a gunfight at a cafe in the seaside village of Foca, Turkey, almost a decade ago, in July 2003.
The toddler was asleep in his pram when an argument broke out at a nearby table and a man opened fire, killing the boy from East Kilbride, South Lanarkshire.
Mr Grimason, who now lives in Aberdeen, spoke out after Syria, Iran and North Korea refused to ratify the treaty at a meeting of the UN in New York, delaying progress towards enshrining a set of rules to regulate the global arms trade in international law.
Whilst a consensus among the 193 UN member states has not been achieved, the treaty is expected to be put to the UN General Assembly next week, where majority approval is likely.
Mr Grimason, who has been attending the treaty talks in New York, said he would remain positive.
“It is frustrating as there was a lot of support for the treaty from most of the other nations,” he said. “But we are staying positive and believe a majority will back it.”