American Samoa is an unincorporated territory of the US located in the South Pacific Ocean. It consists of five main islands and two coral atolls.

Barack Obama has announced plans to create the largest ocean preserve in the world by banning drilling, fishing and other activities in a massive stretch of the Pacific Ocean in a move to protect fragile marine life.

Using presidential authority that does not require action from Congress, the President proposed to expand the Pacific Remote Islands Marine National Monument, which George Bush designated to protect unique species and rare geological formations.

The waters are all considered US territory because they surround an array of remote, mostly uninhabited islands that the US controls between Hawaii and American Samoa.

Carbon pollution is making the world’s oceans more acidic, pollution is threatening marine life and overfishing could wipe out entire species, Obama warned as he vowed to expand the sanctuary during an ocean conservation conference hosted by the State Department.

“If we ignore these problems, if we drain our oceans of their resources, we won’t just be squandering one of humanity’s greatest treasures,” he said in a recorded video message. “We’ll be cutting off one of the world’s major sources of food and economic growth, including for the US. We cannot afford to let that happen.”

The message was played on the second day of the conference, attended by Secretary of State John Kerry and Hollywood star Leonardo DiCaprio.

Sanctuary couldeventually growto roughly 1.5 million square miles

In a related environmental move, Obama vowed to take steps to curb the black market for fish and to combat fraud that hides the origin of sea-food products.

He has not yet settled on the final boundaries for the preserve. The White House said Obama planned to solicit input from fishermen, scientists, politicians, experts in conserv-ation and others before the new protections take effect.

But conservation groups said the potential reach could be massive.

Under maritime law, nations have exclusive economic control over waters that extend 200 nautical miles from their coast. Drawing on a geographic analysis of US possessions in the region, the Pew Charitable Trusts determined that Obama could protect more than 780,000 square miles – almost nine times what Bush set aside when he created the monument.

If Obama were to also protect the waters around the Northern Mariana Islands, the sanctuary could grow to roughly 1.5 million square miles, Pew said.

The executive steps, first reported by the Washington Post, come as Obama searches for ways to leave his second-term mark on the environment despite opposition from many Republicans in Congress.

Presidents have authority to phase out commercial fishing and other activities from US waters under the 1906 Antiquities Act, the same law that allows for land-based national monuments to be created by executive order.

Still, the moves could anger some Republican lawmakers who say Mr Obama is exceeding his authority by going around Congress to promote his agenda on issues like the environment, immigration and gay rights.

Earlier this month he unveiled sweeping new pollution limits on US powerplants amid signs that Congress would not act soon to combat the heat-trapping gases blamed for global warming.

Obama also vowed to create a government programme to combat black market fishing and seafood fraud, in which seafood products are mis-labelled to hide their origin. The White House said 20 per cent of wild marine fish caught each year are part of the black market.