Inspector General Harold W. Geisel said the review will center on whether the State Department and the company followed all US laws and regulations related to the Keystone XL project.

The pipeline would carry oil derived from tar sands in Alberta, Canada, to refineries in Houston and Port Arthur, Texas.

More than a dozen lawmakers requested the review, saying they were disturbed by media reports that a company that performed an environmental review on behalf of the State Department had listed pipeline developer TransCanada as a “major client.”