New Jersey Gov. Chris Christie is ratcheting up his response to revelations that his aides shut down the world’s busiest bridge to punish a political foe, hoping to limit any additional political damage to his administration and his 2016 presidential ambitions.

Christie in his annual State of the State address admitted that “mistakes were clearly made” and vowed to cooperate with all “appropriate inquiries” into the incident. He later announced that he appointed a legal team to work with state and federal investigators and to conduct an independent internal investigation.