Just last week, a bill to move forward with construction of the Keystone XL pipeline, a 1,179-mile (1,897km) pipe that would run from the oil sands in Alberta, Canada, to Steele City, Nebraska, was approved by Congress but then vetoed by President Barack Obama.
The pipeline could carry 830,000 barrels of oil each day. What is it about this pipeline that has created such partisan unrest in Congress?
Since its proposal, the project has pitted Republicans and other supporters, who say it will create much needed jobs, against many Democrats and environmentalists, who warn the pipeline will add to carbon emissions and contribute to global warming.
Find out more about the Keystone XL pipeline, what Canada and the US think about it, and what next steps are being taken to move forward in this BBC article.