Royal Dutch Shell Plc expects to drill in the Arctic off the north coast of Alaska this year, despite legal challenges from environmentalists and native groups, its chief executive said on Thursday.

We have hopes and expectations that drilling can start this season, Jeroen van der Veer told a press conference in London.

Drilling is only possible in summer months as after September ice covers the sea but last week a U.S. federal appeals court ordered Shell to suspend exploration operations.

Opponents of drilling in the Beaufort Sea argue that environmental impact studies carried out by Shell and approved by the U.S. Department of the Interior failed to take seriously the threat posed to bowhead whales and other wildlife.

Van der Veer denied the plan was at odds with the firm's policies, often stated in expensive advertising campaigns, on sustainability and high environmental standards.