NEWARK - A former ally of Gov. Chris Christie has admitted to his role in politically motivated traffic tie-ups near the George Washington Bridge in 2013.

Former Port Authority of New York and New Jersey official David Wildstein made the admissions in a federal court hearing Friday. He admitted to causing significant traffic problems in Fort Lee in September 2013 in retaliation against the city's mayor, who did not endorse Christie's re-election bid, and to using a traffic study as a cover.

Wildstein also admitted that he talked about how the bridge's access lanes could be used as leverage against Fort Lee Mayor Mark Sokolich with former Christie chief of staff Bridget Kelly and Port Authority executive Bill Baroni.

Wildstein pleaded guilty to two conspiracy counts for his role in the scheme.

Revelations about the traffic jams have become a major cloud over the career of Christie, who is considering running for president next year.