US President Barack Obama vetoed a bill that would have allowed the construction of the Keystone XL oil pipeline.
The Republican-dominated congress sent the bill to the president on Tuesday (24 February), which Obama vetoed at the soonest opportunity.
The President vetoed the bill "without any drama or delay," according to White House spokesman Josh Earnest.
The proposed pipeline would have carried oil from Alberta, Canada, to Nebraska, US, where it would have joined pipelines that lead to the US oil hub of Texas.
Republicans have largely backed the project, trumpeting the number of jobs it would create, while Democrats on the whole have rejected the project citing environmental concerns.
Six years in the making, the oil pipeline required federal approval because it crosses an international frontier.
The construction project was narrowly defeated in the Senate in 2014, when the Democratic party held a majority, but it passed the legislature this time around.
The veto is Obama's third of his presidency and the first since Republicans assumed control of both the House of Representatives and the Senate, following mid-term election gains.
Analysts have said the Republicans could try squeezing the Keystone project into critical legislation, in a bid to escape a future veto from the White House.