Christie, 60, enters the race as a decided underdog, six years after his 2016 presidential campaign failed to gain traction amid a crowded field that included Trump. Only 1% of Republicans said he would be their preferred 2024 nominee in a Reuters/Ipsos poll conducted May 9-15.

Ending weeks of speculation about his intentions, Christie will officially launch his campaign at a town hall at Saint Anselm College in New Hampshire on Tuesday, the person familiar with the matter said, confirming an earlier report by Axios.

Christie has urged his party to move on from Trump's baseless claims that the 2020 election was rigged, including in his book "Republican Rescue." That stance could theoretically earn him some support from moderate Republicans eager to turn the page, though it will alienate Trump's still-powerful base of voters.

In March, Christie told Axios he would not vote for Trump in 2024 even if the former president was the Republican nominee. Trump, who announced his campaign last year, leads among Republicans in public polling.

In public appearances, Christie, a former federal prosecutor, has argued he alone has the skill and willingness to go toe-to-toe with the pugnacious Trump directly.

"As we all know here in New Jersey, the governor is a proven leader who fearlessly tells it like it is," Bill Palatucci, a longtime Christie advisor who will chair a political action committee supporting his candidacy, wrote in a message to New Jersey Republican state committee members on Tuesday.

Christie has played the role of attack dog before: in a memorable debate appearance shortly before he ended his 2016 campaign, Christie mocked U.S. Senator Marco Rubio for memorizing his lines, a performance widely seen as irreparably damaging to Rubio's campaign.

In addition to Trump, other Republicans running for president include Florida Governor Ron DeSantis, U.S. Senator Tim Scott and former South Carolina Governor Nikki Haley. Former Vice President Mike Pence and New Hampshire Governor Chris Sununu are among those weighing candidacies.

The nominee would face Democratic President Joe Biden, whose re-election campaign faces no notable intraparty opposition.

A two-term governor from a Democratic-leaning state, the brash and charismatic Christie was once viewed as a rising Republican star who held rare cross-party appeal.

But his second term in office was tarnished by the only-in-New Jersey "Bridgegate" scandal, in which two of his aides were accused of deliberately closing lanes at the heavily trafficked George Washington Bridge to New York City to punish a local mayor who refused to endorse his re-election campaign.

Christie's relationship with Trump and his family has taken a winding path. As the U.S. attorney for New Jersey, he prosecuted Charles Kushner, the father of Trump's son-in-law Jared Kushner, for tax evasion and other crimes.

He and Trump exchanged plenty of barbs during the early stages of the 2016 campaign. But just weeks after dropping out of the race, Christie endorsed Trump over other rivals, giving his candidacy a boost at a critical juncture.

While he served as a campaign adviser, Christie became a political liability late in the race, when witnesses testified during the criminal trial of his aides that he knew of the bridge lane closures at the time. Christie has denied knowing about the plot until afterward.

Nevertheless, he was passed over first for vice president and later for attorney general. Three days after Trump's surprise victory, Christie was fired as the head of Trump's White House transition team.

Since the Jan. 6, 2021, attack on the U.S. Capitol by a mob of Trump supporters, Christie has jabbed at Trump on numerous occasions. He blamed the former president for the Republicans' disappointing showing in the 2022 midterm elections and called Trump's conduct "unacceptable" after a federal jury found Trump liable for sexually abusing the writer E. Jean Carroll in the 1990s.

Christie was also a candidate for the 2012 Republican presidential nomination but was beaten by eventual nominee Mitt Romney.