Republican presidential candidate Donald Trump speaks in Charleston, W.Va. (AP Photo/Steve Helber)

Donald Trump’s presidential campaign announced Monday that New Jersey Gov. Chris Christie (R) will chair the real estate mogul’s White House transition team.

“Governor Christie is an extremely knowledgeable and loyal person with the tools and resources to put together an unparalleled Transition Team, one that will be prepared to take over the White House when we win in November,” the likely GOP nominee said in a statement.

Christie has quickly become one of Trump’s most visible allies, traveling with the reality television celebrity to campaign stops around the country and acting as a surrogate on news shows. He shocked political observers in February when he endorsed Trump’s bid for the White House, which many took as a signal that the GOP establishment would begin to fall in line behind Trump’s insurgent campaign.

What the endorsement ultimately signified, in hindsight, was the sharp fissure that would develop within the Republican establishment over whether Trump can be trusted as the party standard-bearer. Many of the country’s Republican leaders — including several of Trumps’ primary rivals — have said they will sit this election out rather than vote for Trump. House Speaker Paul D. Ryan said last week that he is “not ready” to endorse Trump, even as the party faces a tough general election fight against likely Democratic nominee Hillary Clinton.

Christie’s appointment to the transition team comes as the campaign struggles to shift its messaging to the general election, beyond the bombastic rhetoric that appealed to the GOP base during the primary. In his new role, Christie brings credibility as an experienced state executive to the campaign’s ranks while signaling that the campaign will continue outreach to establishment leaders and aides in Washington.

“I am honored by the confidence being placed in me by Mr. Trump and look forward to putting together a first rate team to assemble an administration to help best serve the President-elect and the nation,” Christie said in a statement released by the campaign.