After months of declining to take a position on the Keystone XL pipeline, Democratic presidential candidate Hillary Clinton says she opposes the construction of the project.

"I think it is imperative that we look at the Keystone XL pipeline as what I believe it is: A distraction from the important work we have to do to combat climate change, and, unfortunately from my perspective, one that interferes with our ability to move forward and deal with other issues," she said during a campaign event in Iowa Tuesday.

"Therefore, I oppose it. I oppose it because I don’t think it’s in the best interest of what we need to do to combat climate change."

Clinton had long cited her former job as secretary of state as a reason to delay weighing in on the deal until the administration formalized its opinion on the project. In July, she said she did not want to “prejudge” President Barack Obama and Secretary of State John Kerry on the result of an administration review of the pipeline’s environmental impact.

But last week, she promised that her decision would be coming “soon” and suggested that she has been growing impatient with the White House for delaying its final verdict on the matter.

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“I have been waiting for the administration to make a decision,” she said last week in Concord, NH. “I thought I owed them that. I worked in the administration. I started the process that is supposed to lead to a decision. I can't wait too much longer. And I am putting the White House on notice. I'm gonna tell you what I think soon because I can't wait. I thought they would have it decided way, you know, way by now and they haven't."

On Tuesday, Clinton acknowledged her past reluctance to weigh in on the matter but said "I feel now I’ve got a responsibility to you and other voters who ask me about this."

Clinton had been under fire from fellow Democratic presidential contenders Bernie Sanders and Martin O'Malley for failing to weigh in on the matter sooner.

Sen. Bernie Sanders responded to Clinton's new support in a statement, saying "As a senator who has vigorously opposed the Keystone pipeline from the beginning, I am glad that Secretary Clinton finally has made a decision and I welcome her opposition to the pipeline. Clearly it would be absurd to encourage the extraction and transportation of some of the dirtiest fossil fuel on the planet."

O'Malley also accused Clinton of being too slow to take a stance.

"On issue after issue--marriage equality, drivers licenses for undocumented immigrants, children fleeing violence in Central America, the Syrian refugee crisis, and now the Keystone Pipeline, Secretary Clinton has followed--not forged--public opinion," he said. "Leadership is about stating where you stand on critical issues, regardless of how they poll or focus group."

Environmental activists vehemently oppose the pipeline, which they say will be vulnerable to leaks, cause harmful effects on the environment and represent a step backward from attempts to address global climate change.

But others, including most Republicans and some pro-business Democrats, say the project would create jobs and carry minimal risk to the environment.

Republican presidential candidate Jeb Bush dinged Clinton on Twitter, saying: