The United States has blocked the release of a landmark assessment of oil and gas activity in the Arctic as it prepares to sell off exploration licences for the Chukchi Sea off Alaska.

Scientists at the release of the censored Arctic Council report in Norway said there was “huge frustration” that the US had derailed a science-based effort to manage the race for the vast energy reserves of the Arctic.

The long-awaited assessment was meant to bring together work by scientists in all eight Arctic nations to give an up-to-date picture of oil and gas exploitation in the high north.

In addition to that it was supposed to give policy makers a clear set of recommendations on how to extract safely what are thought to be up to one quarter of the world’s energy reserves.

Speaking yesterday from Tromso, one of the report’s lead authors, told the Independent newspaper: “They [the US] have blocked it. We have no executive summary and no plain language conclusions. Oil and gas is a sensitive subject.”

One of the lead scientists at the Arctic Council told the paper: “The key message was to be more careful. To check more before you drill for oil and gas in the Arctic.”

No wonder the Bush administration wanted to censor that. Full drilling ahead, says George W.