President Donald Trump has moved swiftly to advance the controversial Keystone XL and Dakota Access oil pipelines, signing executive actions to aggressively overhaul America's energy policy and deal a sharp blow to Barack Obama's legacy on climate change.
Obama had personally halted the Keystone XL project, which was to bring oil from Canada to the US, and major protest demonstrations have frozen work on the Dakota pipeline.
Trump, in his continuing effort to undo the past eight years of a Democratic president, invited the Keystone builder, TransCanada, to resubmit its application to the State Department for a presidential permit to construct and operate the pipeline.
Obama halted the proposed pipeline in late 2015, declaring it would undercut US efforts to clinch a global climate change deal that was a centrepiece of his environmental agenda.
Trump also ordered on Tuesday that the US Army Corps of Engineers quickly review and approve construction and easement requests for the Dakota Access pipeline, a project that has led to major protests by native American groups and their supporters.
"From now on we are going to start making pipelines in the United States," Trump said from the Oval Office, where he also vowed to require the actual pipe for Keystone to be manufactured in America.
Republicans and also Democrats in energy-producing states hailed Trump's actions on the pipelines as long-awaited steps to boost jobs and move the country toward energy independence.
But environmental groups and Native American tribes who have fought both projects for years pledged to defy Trump.
"President Trump will live to regret his actions today," said Michael Brune, executive director of the Sierra Club.
"Unwittingly he is beginning to build a wall - a wall of resistance. This fight is far from over."
The 1900km Keystone XL pipeline would run from Canada to Nebraska, where it would join other lines already leading to refineries along the Gulf Coast.
Trump has moved swiftly this week to make good on some of his core campaign pledges he says are aimed at creating jobs and growing the economy.
On Monday, he signed a memorandum withdrawing the US from the Trans-Pacific Partnership trade pact, a proposed accord with 11 Pacific Rim countries and another of Obama's prized accomplishments.
Yet even as Trump moves to implement his agenda, he is still making false claims.
During a reception with members of congress at the White House Monday evening, Trump again claimed the reason he had lost the popular vote to Democratic rival Hillary Clinton was that three million to five million immigrants living in the US illegally had voted.
That is according to a Democratic aide familiar with the exchange who spoke on condition of anonymity to discuss the private meeting.
There is no evidence to support Trump's claim.
On Tuesday, Trump summoned the heads of the big three American auto makers, General Motors, Ford Motor Co and Fiat Chrysler, for a breakfast meeting at the White House.
He pledged to scrap regulations and reduce taxes on corporations that keep jobs in the US, though he did not specify his plans for either.
