Barack Obama has permanently banned offshore oil and gas drilling in the “vast majority” of US-owned northern waters.
The outgoing president designated areas in the Arctic and Atlantic oceans as “indefinitely off limits” to future leasing.
The move is widely seen as an attempt to protect the region before Barack Obama leaves office in January.
Donald Trump’s supporters could find it difficult to reverse the decision.
In a joint announcement with Washington, Canada also committed to a similar measure in its own Arctic waters.
According to the White House, the decision was for “a strong, sustainable and viable Arctic economy and ecosystem”.
It cited native cultural needs, wildlife concerns, and the “vulnerability” of the region to oil spills as some of the reasons for the ban.
However, while Canada will review the move every five years, the White House insists President Obama’s declaration is permanent.
The decision relies on a 1953 law which allows the president to ban leasing of offshore resources indefinitely.
During the election campaign, Donald Trump said he would take advantage of existing US oil reserves, prompting concern from environmental groups.
Supporters have already suggested that any attempt to reverse the “permanent” decision outlined by the law would be open to a legal challenge.
Reacting to the Arctic declaration, Friends of the Earth said:
“No president has ever rescinded a previous president’s permanent withdrawal of offshore areas from oil and gas development.
“If Donald Trump tries to reverse President Obama’s withdrawals, he will find himself in court.”
However, the American Petroleum Institute said “there is no such thing as a permanent ban,” and that it hoped Donald Trump’s administration would simply reverse the decision.
The president-elct has also raised fears among some environmental campaigners through his choices for senior White House roles.
Exxon Mobil CEO Rex Tillerson has been named his secretary of state. His energy secretary, Rick Perry, has previously called for less regulation of the oil industry in his role as governor of Texas.
Environmental groups strongly criticized both appointments.
Very little oil drilling currently takes place in the Arctic region, as it is more expensive and difficult than other available options.
VIDEO Around 30 Greenpeace activists have been accused by Russian prosecutors of piracy and will be prosecuted for trying to board an Arctic oil platform.
Russia’s Investigative Committee, modeled on the FBI, will question the activists.
The Greenpeace ship, Arctic Sunrise, is being towed to the port of Murmansk.
Around 30 Greenpeace activists have been accused by Russian prosecutors of piracy and will be prosecuted for trying to board an Arctic oil platform
Committee spokesman Vladimir Markin said “all those who assaulted the platform, regardless of nationality, will be prosecuted”.
The campaigners were detained on Thursday along with their ship after two Greenpeace activists tried to climb onto a Gazprom offshore platform, in a protest against oil drilling in the Arctic.
Arctic Sunrise was raided by armed Russian men in balaclavas who abseiled down from helicopters. The ship was seized in the Pechora Sea, near the rig.
Greenpeace said the Russian authorities “are holding 30 of our activists”, though that figure was not confirmed by Russian officials.
The Ecuadorian conservation plan that would have paid the country not to drill for oil in previously untouched parts of Yasuni National Park in the Amazon rainforest has been abandoned.
President Rafael Correa said rich nations had failed to back the initiative, leaving Ecuador with no choice but go ahead with drilling.
The park is one of the most biodiverse areas in the world.
Hundreds of people gathered in Quito to protest against Rafael Correa’s decision.
Oil exploitation has been taking place in parts of the Yasuni National Park, which covers nearly 3,860 sq miles, since the 1970s.
Oil is Ecuador’s main export. Exploitation of the new area is expected to start in the coming weeks.
The UN-backed scheme to attract donations to forego drilling in the east of the park was launched by Rafael Correa in 2010.
The aim was to raise $3.6 billion, 50% of the value of the reserves in the park’s Ishpingo-Tambococha-Tiputini (ITT) oil field, over 13 years.
But in a televised news conference on Thursday, Rafael Correa said the initiative had attracted only a fraction of the cash it had aimed to raise.
With only $13 million so far in actual donations, he said he had no other option but to abandon the fund as “the world has failed us”.
The Ecuadorian conservation plan that would have paid the country not to drill for oil in previously untouched parts of Yasuni National Park in the Amazon rainforest has been abandoned
“I have signed the executive decree for the liquidation of the Yasuni-ITT trust fund and through it, end the initiative,” the president said in a televised address.
He called the decision one of the most difficult he had had to take as president.
“It was not charity that we sought from the international community, but co-responsibility in the face of climate change,” Rafael Correa said.
The president added that the oil exploration would leave most of the park untouched, affecting less that 1% of its area.
Environmental activists demonstrated outside the presidential palace in the capital, Quito, about the announcement.
According to the Yasuni-ITT trust fund, 78% of Ecuadorians are against drilling in the park, which is also home to indigenous communities, including the Tagaeri and the Taromenane.
The fund, administered by the UN Development Programme, argues that stopping the drilling would prevent more than 400 million tonnes of carbon dioxide from going into the atmosphere.
A scientist working for the US-based Center for International Environmental Law said it was “deeply disappointing” the funding initiative had failed.
“The Yasuni-ITT Initiative was the lone exception to the relentless expansion of hydrocarbon projects deeper into the most remote tracts of the western Amazon,” Matt Finer told AP.
“Now there is really no viable alternative to stop the wave of drilling slated for the most biodiverse region of the world.”
Kenya has announced discovery of oil for the first time in the country after exploratory drilling by Anglo-Irish firm Tullow Oil.
President Mwai Kibaki said the discovery was made in the country’s north-western Turkana region.
Mwai Kibaki said it was “the first time Kenya has made such a discovery” and called it a “major breakthrough”.
Kenya is a regional business and tourist hub with the largest economy in East Africa, although its relative wealth is not based on mineral riches.
The Kenyan president said Tullow would drill more wells to establish the commercial viability of the oil.
“It is… the beginning of a long journey to make our country an oil producer, which typically takes in excess of three years. We shall be giving the nation more information as the oil exploration process continues,” Mwai Kibaki said.
Kenya has announced discovery of oil for the first time in the country after exploratory drilling by Anglo-Irish firm Tullow Oil
Tullow Oil, which also struck oil in neighboring Uganda, said the Kenyan find had exceeded their expectations.
“This is an excellent start to our major exploration campaign in the East African rift basins of Kenya and Ethiopia,” said Angus McCoss, the company’s exploration director.
“To make a good oil discovery in our first well is beyond our expectations and bodes well for the material programme ahead of us.”
Tullow has found oil in, or off the coast of, a number of African countries, including Ghana and Sierra Leone.