Gov. Chris Christie (R-N.J.) discusses reaction to his appearance on Super Tuesday with Donald Trump in a news conference. (Reuters)

Chris Christie wants the world to know that he was not being held hostage this week.

Under fire from fellow establishment Republicans for endorsing Donald Trump for president, the New Jersey governor held a news conference Thursday in which he issued a wide-ranging defense of his support for the GOP front-runner and his frequent absences from his home state.

In one prominent appearance this week, Christie introduced “Mr. Trump” and then stood behind the mogul as he celebrated seven Super Tuesday primary victories that have put him on a path to be the Republican nominee. Christie’s expressions seemed pained, glassy and vacant, leading to mocking suggestions on social media and cable television shows that the governor looked like he was regretting his endorsement or being held against his will.

“I want everyone to know for those who were concerned: I wasn’t being held hostage, I wasn’t upset. I wasn’t angry. I wasn’t despondent,” Christie said Thursday during a long news conference at the statehouse in Trenton, N.J.

“I was not sitting up there thinking, ‘Oh, my God, what have I done?’ ” Christie added, saying he was “happy that we had done as well as we had done that night.”

Donald Trump celebrates his Super Tuesday victories in a speech in Palm Beach, Fla. (Reuters)

Holding a news conference in which he had to explicitly say that he wasn’t a prisoner of Trump was another awkward episode for a governor who was once hailed as a rising Republican star but is now a failed presidential aspirant with dismal approval ratings in his home state. According to a poll from Fairleigh Dickinson University, only 35 percent of New Jerseyans surveyed approve of how Christie is doing his job.

Most of the state’s major newspapers have turned on him. In a joint editorial this week, six ­Gannett-owned papers called on Christie to resign or face a recall effort. The editorial said Christie spent 261 days outside New Jersey last year as he pursued his presidential bid.

“What an embarrassment. What an utter disgrace,” the papers said.

The state’s largest newspaper, the Star-Ledger of Newark, owned by Advance Publications, joined the fray Thursday with its own editorial calling on Christie to quit, saying he had abandoned his duties in the midst of a fiscal crisis in Atlantic City and the state.

“Gov. Chris Christie has made it abundantly clear that governing New Jersey is a distant second priority for him, far behind the demands of his personal ambition,” the Star-Ledger said. It called the Trump endorsement “craven” and the “moment when [Christie] lost any last shred of credibility.”

Some of Christie’s backers and fellow Republicans in the state also are going after him.

Donald Trump, accompanied by Chris Christie, left, takes questions from members of the media during a news conference on Super Tuesday primary election night in Palm Beach, Fla. (Andrew Harnik/AP)

Hewlett Packard Enterprise chief executive Meg Whitman, one of Christie’s top supporters, issued a statement this week blasting him for an “astonishing display of political opportunism” in endorsing Trump, whom Whitman labeled a “dishonest demagogue.”

One Republican legislator said Christie has to make a decision: Do his job as governor or campaign for Trump full time.

“I think he’s doing a disservice to the residents of New Jersey who elected him twice to be governor,” state Sen. Christopher “Kip” Bateman told the Record of Woodland Park.

“I think he should make up his mind. If he wants to be a surrogate for Trump, that’s fine,” he said. “But he can’t neglect his duties as governor.”

Christie dropped out of the presidential race after a poor showing in the New Hampshire primary last month. He enthusiastically backed Trump in a surprise endorsement in Fort Worth last week.

“Donald Trump is someone who, when he makes a promise, he keeps it,” Christie said. “No one is going to get inside this guy’s head. There is no better fighter than Donald Trump.”

Christie said Thursday that he had made a choice and people will have to live with it. He also said he is “back to work” in New Jersey and not a full-time surrogate for Trump.

“I’ve made a choice. Some people agree with that choice. Some people disagree with that choice,” he said, saying he believes Trump is the best candidate to beat Democratic front-runner Hillary Clinton.

Christie said he makes his opinions known to Trump.

“When I disagree with him, I tell him. And when we’ve been together over the last couple days, I tell him my opinions on things,” Christie said.

Brigid Harrison, a professor of political science at Montclair State University, said Christie has little political capital left in New Jersey and, likely, nationwide.

“He essentially has committed political suicide with the establishment,” she said. “He is now damaged goods.”

Harrison said that Christie, who loves attention, may be playing second fiddle to someone who wants it even more.

“Christie is typically unwilling to share the spotlight with anyone,” she said. “I think he found the only other person in the world who is less willing to share the spotlight than he is.”