There had been complaints that the treaty, which bans the manufacture, export, import and supply of land-mines, would not become law in the UK before the anniversary of the death of Diana, Princess of Wales, who had campaigned for the abolition of land-mines.
Ministers had said they would legislate to ratify the treaty as soon as parliamentary time became available, but it had not been thought there would be any action before the autumn.
Mr Robertson told an international conference in London on land-mine elimination that ministers were actively looking at ways of pushing through the necessary legislation in the next month.
"We are looking at this matter with some degree of urgency and we have not ruled out taking more rapid action than was previously assumed," he told the conference organised by the British Red Cross.
Mr Robertson told the conference that ratifying the Convention remained one of the Government's "key priorities" and that he would discuss it with other ministers yesterday.
"We are looking very carefully at how we could get the ratification through as quickly as possible," he said.
Ministers had argued that the crowded legislative programme - including the measures needed to implement the Northern Ireland peace settlement - meant that ratification would have to wait until the next parliamentary session.
Mr Robertson said there were still legal problems to be ironed out over the issue of British troops working alongside allied forces which had not ratified the convention.
Britain is one of 126 states to have signed the Ottawa Treaty, but so far only 20 have ratified it, although France is expected to do so tomorrow.
It requires 40 states to ratify a treaty before it can be enforced and Mr Robertson said he still hoped that Britain would be among that leading group. He paid tribute to the role played by the Princess of Wales in generating the international will to secure the Ottawa Convention.
"She contributed enormously to bringing the world's attention to the devastating effects of anti-personnel land-mines and thereby to the success of the Ottawa process," he said.