Rolland Schmitten, U.S. delegate to the International Whaling Commission, said the Icelandic government informed American and other ambassadors that it plans to take 38 minke whales this summer.
"We oppose it. We're disappointed," Schmitten said in a telephone interview. "It's not relevant science, it's not necessary."
While countries don't need commission approval for scientific whaling, they normally present their plans to the agency. Iceland did so, and commission members last month voted disapproval of its plan to take 250 whales from three species, Schmitten noted.
"They're unilaterally granting themselves this authority," he said.
Helgi Agustsson, Icelandic ambassador to the United States, said the catch is necessary to learn as much as possible about the region's whale stock. Such catches yield information about whales' health and how many whales there are in the area, for example.
Iceland's Ministry of Fisheries said its quota of 38 minkes was "clearly a minimalist approach" that "shows Iceland's willingness to be constructive and compromise when it comes to whaling issues."
Iceland stopped commercial whaling in 1989 under an international moratorium. When it rejoined the whaling commission in October, the government said it would not be bound by the moratorium after 2006.
The ministry said despite disagreement on the commission about its scientific hunting plans, members had agreed that the proposed catch was unlikely to have a significant effect on minke whale stocks.
Fred O'Regan, president of the International Fund for Animal Welfare, said there was no scientific basis for Iceland's plan.
"Whales already face constant threat from pollution, entanglement in fishing nets, habitat loss and other dangers," O'Regan said.
The decision could also harm Iceland's eco-tourism industry, he said. Iceland has had a growing trade in tourists visiting to view whales, puffins and other wildlife.
Japan also practices scientific whaling, and the United States opposes it, said Schmitten, director of the office of habitat conservation at the National Oceanic and Atmospheric
The commission has a moratorium on commercial whaling in an effort to allow stock to rebuild from centuries of whale hunting.
But debate continues among various countries about where whale stocks are large enough yet for a catch to resume.
Iceland had quit the international commission but resumed membership last October. It said at the time it was giving itself a special exemption for scientific whaling.
Schmitten said that wasn't expected to begin until 2006.
"It was a total surprise to the U.S. when, in early summer, they notified us they intended to start in the near future," he said. "We urged they not do that unilaterally."
By Randolph E. Schmid