OSAKA — Japan admitted to the United States that actions by the activist group Sea Shepherd had curtailed its annual whale hunt but opposed Washington's efforts to have it politically engage fellow whaling nation Iceland to reduce its catch, WikiLeaks cables revealed Monday.

Negotiations between Japan and the U.S. over Sea Shepherd and the future of the International Whaling Commission in November 2009 and last January were the subjects of the first U.S. diplomatic cables from the U.S. Embassy in Tokyo released by WikiLeaks.

The Tokyo cables and a separate cable from the U.S. State Department show that in early November 2009, less than two weeks before a summit between then Prime Minister Yukio Hatoyama and U.S. President Barack Obama, the U.S. met Foreign Ministry officials to request political engagement from Japan on reaching a compromise within the IWC.