REUTERS/Andrew Cullen
In January, President Donald Trump signed an executive order advancing the pipeline and promised that 28,000 construction jobs would be created.
The move overturns a directive by former President Barack Obama to halt the pipeline.
"We greatly appreciate President Trump's Administration for reviewing and approving this important initiative and we look forward to working with them as we continue to invest in and strengthen North America's energy infrastructure," said CEO Russ Girling in a statement.
TransCanada shares gained 1% in premarket trading.