An advocacy group said Monday it filed a request for information from the U.S. State Department on its assessment of the planned Keystone XL oil pipeline.

The State Department is tasked with vetting a pipeline TransCanada plans to build across the U.S.-Canadian border. A southern U.S. leg of the project is already in service, though the cross border section needs federal approval.

In June, the State Department published revisions to its impact statement on Keystone XL. Advocacy group Friends of the Earth says the amendment includes an assessment that more deaths could occur from the increase in crude oil transport by rail that would result in denying construction for Keystone XL.

Friends of the Earth campaigner Luisa Abbot Galvao said the State Department cherry-picked the data on rail, but ignored information that suggests Keystone XL would result in an increase in greenhouse gas emissions.

"This narrow play on numbers reflects an attempt to legitimize a false choice between two grim alternatives when scientists are telling us that fossil fuels must be kept in the ground to avoid further climate disruption," she said in a statement.

Friends of the Earth said it filed a Freedom of Information Act request with the State Department seeking information on its June assessment.

The State Department in April said "uncertainly created by the ongoing litigation" over the pipeline's route through Nebraska means a final decision is delayed.

The state of Nebraska is appealing a judge's decision changing the route -- and that could mean no final decision will be made until after the November congressional elections. The final decision is in President Obama's hands because the pipeline crosses an international border.