US President Donald Trump signed orders designed to advance construction of the Keystone XL pipeline from Canada into the US and the Dakota Access pipeline. 
Both had been blocked by his predecessor Barack Obama over environmental concerns. 
The Keystone project had been a long-standing point of dispute between Republicans and Democrat Obama, who rejected it after years of review in 2015 because of climate change concerns. 
The proposed Keystone XL pipeline was slated to have carried oil from Canada's tar sands in Alberta to the Midwestern state of Nebraska, where an existing pipeline would carry the Canadian oil to refineries in Texas. 
The Dakota Access Pipeline was the site of protests last year by Native American groups concerned about the impact on their lands and water. Last month, the US Army Corps of Engineers blocked the construction, calling for alternate routes to be considered.