A spokesman for Teekay Corp., the ship's owner, said the Australian Spirit started having problems Tuesday evening.
Jonathan Anthony said the tanker was about 70 kilometres southeast of Halifax early Wednesday afternoon and it wasn't near any other ships.
One tugboat, the Atlantic Larch, had reached the vessel and another tugboat that is capable of towing the tanker was expected to arrive by the evening, he said.
"The crew and cargo are safe. ... We obviously take it very seriously, but there's no imminent danger," he said in an interview from Vancouver.
Keith Laidlaw, an environmental response officer with the coast guard, said if the steering can't be fixed then the tugs will make a towing plan to bring the tanker into harbour for repairs.
The vessel was not in danger of breaking up and its drift towards shore had slowed as seas calmed, he said, adding that if the ship is towed that wouldn't begin until Thursday morning.
Laidlaw said the vessel's towing plan would have to be approved by Transport Canada.