WASHINGTON — The State Department issued a revised environmental impact statement for the 1,700-mile Keystone XL pipeline on Friday that makes no recommendation about whether the project should be built but presents no conclusive environmental reason it should not be.

The 2,000-page document also makes no statement on whether the pipeline is in the United States’ economic and energy interests, a determination to be made later this year by President Obama.

But it will certainly add a new element to the already robust climate change and energy debate around the $7 billion proposed project. The new report does not make any policy recommendations, but its conclusion that the environmental and climate change impacts are manageable could provide Mr. Obama political cover if he decides to approve the pipeline.

Although the study will help guide the president’s decision, it does not make the politics any easier. Environmental advocates and landowners along the route have mounted spirited protests against the project, including a large demonstration in Washington last month. They say they view Keystone as a test of Mr. Obama’s seriousness about addressing global warming.