The decision caps a years-long fight between environmental groups and energy industry advocates over the pipeline's fate that became a proxy battle over global warming. It marks one of the biggest steps taken to date by the Trump administration to prioritize economic development over environmental concerns. The U.S. State Department issued a permit to TransCanada to build the Keystone XL pipeline between Canada and the United States on Friday, March 24.

Former president Obama rejected the construction

“Today we begin to make things right,” President Trump said Friday morning shortly after the State Department granted the pipeline giant TransCanada a permit for Keystone construction, a reversal of Obama administration policy.

The project, which dates back to 2008, is expected to connect nearly 1,900 km of Alberta's oil sands with the Nebraska pipeline system.

Former President Barack Obama had blocked it, saying it would have no impact on gasoline prices and would contribute to greenhouse gas emissions. He also said it would undermine American leadership in curbing reliance on carbon fuels. His successor Trump revived the implementation in a decree signed on January 24, four days after his inauguration, ensuring that he would create thousands of jobs.

According to a report by Reuters, Donald Trump has claimed the project would create 28,000 jobs in the United States. But a 2014 State Department study predicted just 3,900 construction jobs and 35 permanent jobs.

The White House has said the pipeline is exempt from a Trump executive order requiring new pipelines to be made from U.S. steel because much of the pipe for the project has already been built and stockpiled.

Canadian Prime Minister welcomes the news

Canadian Prime Minister Justin Trudeau welcomed the news in a scrum with reporters on Friday, saying the government is "very pleased with the announcement coming out of the United States."

The multibillion-dollar pipeline, first pitched in 2008, would bring more than 800,000 barrels per day of heavy crude from Alberta into Nebraska, linking to an existing pipeline network feeding U.S. refineries and ports along the Gulf of Mexico along the entire almost 1,900-kilometer route.