US president Donald Trump has signed executive orders to advance construction of the Keystone XL and Dakota Access oil pipelines.
Both projects had been blocked by the Obama administration, partly due to environmental concerns. The orders are subject to renegotiations of the terms and conditions involved.
Mr Trump also signed a notice requiring the materials for the pipelines to be constructed in the United States.
The new US president also announced that he plans to nominate a justice for the Supreme Court next week, moving swiftly to try to fill the seat left vacant by the death of Justice Antonin Scalia.
Mr Trump is summoning top senators to the White House later to discuss his upcoming nomination.
He has sought to focus his first full week in office on jobs and the economy. Republicans, as well as some unions, have cited the pipeline projects as prime opportunities for job growth.
Former president Barack Obama had halted the proposed Keystone XL pipeline in late 2015, declaring it would have undercut US efforts to clinch a global climate change deal that was a centrepiece of his environmental legacy.
The pipeline would run from Canada to Nebraska where it would connect to existing lines running to US refineries on the Gulf Coast. The US government needs to approve the pipeline because it would cross the nation’s northern border.
Separately, late last year, the US Army corps of engineers declined to allow construction of the Dakota Access pipeline under Lake Oahe, saying alternative routes needed to be considered.
The Standing Rock Sioux tribe and its supporters said the project threatens drinking water and Native American sites. Energy Transfer Partners, the company that wants to build the pipeline, disputes these claims and says the pipeline will be safe.
The pipeline is to carry North Dakota oil through South Dakota and Iowa to a shipping point in Illinois.
Earlier, Mr Trump caused more controversy after making unsubstantiated claims about election fraud – even as he reached out to Democratic rivals, business leaders and union chiefs in a bid to sell his policies.
During a bipartisan reception at the White House on Monday evening, Mr Trump is understood to have claimed that he lost the popular vote to his Democratic rival Hillary Clinton because three to five million illegal immigrants had voted in the November election.
There is no evidence to support Mr Trump’s claim, which was reported by a Democratic aide.
The assertion appears to be part of a developing pattern for Mr Trump and his new administration in which falsehoods or otherwise unverifiable claims overshadow his efforts to build bridges.
Mr Trump began his first full week as president playing host to business, union and Congressional leaders at the White House. Again and again, he ordered aides to summon journalists from their West Wing workplace at a moment’s notice for unscheduled statements and photo opportunities.
Among those meetings was a reception at the White House for congressional leaders of both parties.
Mr Trump is also expected to speak by phone with Indian prime minister Narendra Modi and meet his newly sworn-in CIA director Mike Pompeo.
Mr Trump’s comments on the popular vote were similar to claims he made on Twitter in late November that he had won the electoral college in a “landslide” and also “won the popular vote if you deduct the millions of people who voted illegally”.
Mrs Clinton won the popular vote by nearly 2.9 million votes, despite losing the electoral college. There is no evidence that voter fraud significantly affected the vote.
Earlier, Mr Trump charted a new American course abroad, withdrawing the US from the sweeping Trans-Pacific Partnership (TPP), using one of his first actions in office to reject a centrepiece of his predecessor Barack Obama’s attempts to counter China and strengthen US ties in Asia.
For Mr Trump, the move fulfilled a central campaign promise. He has repeatedly said the 12-nation trade pact – which was eagerly sought by US allies in Asia – was detrimental to American business interests.
As Mr Trump signed the paperwork in the Oval Office, he said: “Great thing for the American worker what we just did.”
In addition to his executive action on TPP, Mr Trump signed memorandums freezing most federal government hiring – with the exception of the military – and reinstating a ban on providing federal money to international groups which perform abortions or provide information about the option.