New Jersey Gov. Chris Christie, facing what may be the biggest test of his political career, responded Wednesday to emails that indicate a top aide was involved in controversial lane closures last year that snarled traffic, by saying the intervention was "unsanctioned" and "unacceptable" -- and claiming he would hold people "responsible."

The emails involving the governor's deputy chief of staff, Bridget Anne Kelly, surfaced in a report by The New York Times. They pertained to a bizarre incident in September, when lanes at the George Washington Bridge from Fort Lee, N.J., were closed for four days. Christie faced accusations that the lanes were blocked in retaliation over Mayor Mark Sokolich's refusal to endorse him for re-election last November.

The prospective Republican presidential candidate maintained Wednesday that he was "misled" and had no knowledge of his staff's apparent involvement.

"What I've seen today for the first time is unacceptable," Christie said. "I am outraged and deeply saddened to learn that not only was I misled by a member of my staff, but this completely inappropriate and unsanctioned conduct was made without my knowledge. One thing is clear: this type of behavior is unacceptable and I will not tolerate it because the people of New Jersey deserve better. This behavior is not representative of me or my Administration in any way, and people will be held responsible for their actions."

The report Wednesday fueled Democratic accusations that the closures were political retribution against the local mayor. The local scandal threatens to become a national issue for Christie as he weighs a possible presidential run in 2016.

The Democratic National Committee responded to Christie's statement by saying it neither explains or apologizes for the scandal, and called on Christie to give the public more than "his customary bluster and deflection."

"It’s time that the so-called ‘straight talking’ governor takes some of his own advice – and he can do that by cooperating with all investigations surrounding the politically-motivated lane closures and ensuring his staff and associates do the same," a DNC spokesman said.

The New York Times reported that emails show his deputy chief of staff suggested closures to the Port Authority of New York and New Jersey two weeks before the incident.

"Time for some traffic problems in Fort Lee," she wrote to Christie confidant David Wildstein, according to the Times. At the time, Wildstein was on the Port Authority; he has since resigned.

The George Washington Bridge, which connects New Jersey and New York City, is one of the most heavily traveled commuter routes in the country, handling nearly 300,000 vehicles a day. The closures in September caused massive gridlock, leaving commuters stuck in traffic for hours.

It was the Port Authority that ordered the closures, claiming they were part of a traffic study.

The email messages also reportedly show New Jersey officials reacting after the closings were reversed.

"The New York side gave Fort Lee back all three lanes this morning. We are appropriately going nuts," Wildstein reportedly wrote to Kelly. "[Port Authority Chairman David] Samson helping us to retaliate."

Rep. Bill Pascrell, D-N.J., said Wednesday that his constituents "were put in jeopardy because of some jerk who made a decision."

Though Christie denies involvement, Democrats have tried to use the incident to undercut his image as a bipartisan problem-solver -- amid expectations that he may run for president in 2016.

Republican operative Hogan Gidley told The Associated Press that even if Christie navigates the current controversy well,  the issue would likely come back to haunt during in a presidential run.

"I don't necessarily think it's Christie's policy that's going to ultimately catapult or sink his campaign; I think it's his personality," said Gidley, a senior adviser to 2012 presidential candidate Rick Santorum.

In December, Sen. Jay Rockefeller, D-W.Va., formally asked the Port Authority to "answer for" the incident.

"Unwarranted lane closures with no public notice can have serious ramifications on interstate commerce and safety in the region," he said at the time. "The gravity of this situation demands a comprehensive investigation."

Days earlier, the Democratic National Committee released a video on the traffic jam, asking whether it was "Chris Christie's political payback?"