Freshman Sen. Joe Donnelly, D-Ind., has joined other senators in writing a letter to President Obama to urge his approval of the Keystone XL oil pipeline.

Donnelly said Thursday in a statement that the proposed pipeline “means jobs for American families and energy security for our country.”

Critics contend the pipeline, which would stretch from the tar sands in Alberta, Canada, across six states to refineries along the Gulf of Mexico, would pose environmental risks in the event of spills, send most of the oil it transports to foreign markets and contribute to global warming.

Donnelly said he and 10 other senators – nine Democrats and three Republicans – signed the letter Wednesday after Nebraska officials approved a new pipeline route that would avoid the state’s Sand Hills, an environmentally sensitive area.

In all, 53 senators have signed the letter, including Sen. Dan Coats, R-Ind. Donnelly’s predecessor, Sen. Richard Lugar, R-Ind., was an avid supporter of the pipeline proposed by Calgary, Alberta-based TransCanada.

The Obama administration last year delayed action on the $7 billion pipeline because of concerns about its prospective path through Nebraska wetlands and the shallow aquifer that feeds them.