* Arctic conditions pose unique response challenges -report
* Lawmaker wants stronger oversight of well containment
WASHINGTON, March 30 (Reuters) - The U.S. government must consider the harsh conditions of the Arctic and lack of containment infrastructure as it weighs Royal Dutch Shell's plans to drill off the Alaska coast, a report said on Friday.
The Government Accountability Office, Congress' investigative arm, said in its report that the oil industry's ability to cap out-of-control wells in deep water has improved since the BP oil spill dumped 4.9 million barrels of oil into the Gulf of Mexico in 2010.
But the report said the ice, the cold, and the lack of extensive infrastructure in the Arctic are obstacles not found in the Gulf.
"The existence of different types of risk and the limited response infrastructure pose additional challenges Interior will have to address to conclude that it is providing sufficient oversight," the report said.
The Interior Department approved Shell's oil-spill response plan for the Alaska's Beaufort Sea on Wednesday and approved the company's spill-response plan for the Chukchi Sea earlier this year.
Shell is working to begin drilling off Alaska's coast this summer after repeated regulatory delays for the company's Arctic exploration program. It will still need well-specific permits before it starts drilling.
The company is taking additional measures to contend with the Arctic conditions, including having well-containment equipment in the region to quickly respond to an emergency.
Still, "these dedicated capabilities do not completely mitigate some of the environmental and logistical risks associated with the remoteness and environment of the region," the report said.
Environmentalists and some lawmakers have raised concerns that the government and the oil industry are still not adequately prepared to contain a spill in deep waters or in the Arctic.
"The Department of Interior needs to do more than accept industry's assurances that blowout containment technology will be available, and I call on the Department to beef up its oversight and enforcement of these activities," Congressman Edward Markey, the top Democrat on the House Natural Resources committee, said in response to the report.
The report said the department has strengthened its oversight of the oil industry's containment capabilities, but it needs to lay out a timeframe for including well containment in its unannounced spill drills.