The Canadian government has joined the last-ditch effort by activists to prevent oil drilling in Alaska's Arctic National Wildlife Refuge (ANWR). Citing a 1987 bi-lateral agreement to protect the Porcupine River caribou herd that migrates from the Canadian Yukon to ANWR's coastal plain each year, Canadian Foreign Affairs Minister Pierre Pettigrew is urging the U.S. to honor its 18-year commitment by halting its drilling plans.