Shell aims to launch a drilling campaign in the coming months in the Beaufort and Chukchi seas off the Alaskan coast.
Shell President Marvin Odum told the Platts news service the program might get scaled back from five exploratory wells to three if there is late ice cover in the region.
"It's a little ironic, isn't it, that this is the year it looks like we'll finally move forward with the drilling process and what we find through our analysis is there's more ice in the Arctic this year than there has been in the last decade," he said.
Odum said the ice might push the campaign back a month.
Environmental groups have protested Shell's operations, saying the risk to the arctic ecosystem is too great.
Odum, however, said potential oil spill response plans were top-notch.
"Nobody's more concerned about it than us," he said.
Climate change trends are leading to melting arctic sea ice, exposing vast unexplored areas thought to hold reserves of oil and natural gas.