“Joe is ready to go,” said this confidant, who spoke on the condition of anonymity to be candid. “This could be his crowning achievement, this summit. It’s time. Joe Hagin has served his time.”

White House press secretary Sarah Huckabee Sanders said “there are no personnel announcements at this time.”

Hagin could not be reached for comment in Singapore.

Hagin, a former deputy chief of staff to President George W. Bush, was brought into the Trump White House to add some gravitas and operational know-how when most Trump aides had little to no White House experience.

Trump named Hagin to the post the day of his inauguration in January 2017 and Hagin pledged to serve at least a year in the untested administration. In the early days of the presidency, colleagues often called Hagin “the grown-up in the room”.

Hagin, whose middle name is Whitehouse, had the bona fides. He worked in the same post, deputy chief of staff over operations, for George W. Bush from 2001 to 2008.

He had become a trusted lieutenant in the Bush family, from his days in 1979 working as a “body man” for Bush’s father, George H.W. Bush, when he unsuccessfully ran for president. He later became a personal aide to the elder Bush when he became vice-president in 1981.

But Hagin struggled – in much the same way chief of staff John Kelly has – in trying to press an unruly group of Trump friends and outside advisers to follow the norms and protocol of past White Houses, several advisers said.

Some long-time Trump friends chafed at the order Kelly and Hagin tried to instil on Trump’s schedule, their limits on random visits and their rejection of special requests. Some viewed Hagin as far too aligned with the Bush political orbit, and more loyal to that political dynasty than to Trump.

Several weeks ago, some Trump loyalists began circulating a meme that showed a red, white and blue campaign banner with the names of Hagin and John DeStefano, an assistant to the president and a close Hagin ally. It read: “Hagin-DeStefano: Make America Bush Again.”

Still, Trump has come to trust Hagin’s operational capabilities, seeing him as a steady hand who can execute complicated tasks, such as arranging the logistics for the Singapore summit.

A senior White House official described Hagin as a force for calm and as a reliable resource for institutional knowledge on a variety of topics, not only about operations.

Hagin’s relationship with first lady Melania Trump’s office was sometimes tense, according to people familiar with their work. Hagin sometimes denied the first lady’s office’s operational requests.

A White House official said the first lady and Hagen have good relations.

Hagin allies said all White Houses have warring camps, and disputes often crop up between the president’s aides in the West Wing and the first lady’s team in the East Wing. They said some of Hagin’s foes are exaggerating those tensions because they don’t like the order he has tried to impose.

“Joe sticks to the rules,” the associate said. “This White House doesn’t like that … They say, ‘We’re going to make America great again. Get out of our way.’”

Hagin, who prefers to work behind the scenes and rarely talks to the press, has been a key planner for the North Korea summit.

He led a US delegation to try to arrange logistics for the event in May, and the summit appeared in danger when the North Korean delegation didn’t show up.

But Hagin returned with his advance team over Memorial Day weekend for another try, a persistence that eventually made it possible last week for Trump to declare the June 12 meeting was back on.

The deputy director job at the CIA came open with the rise of Gina Haspel to the director’s position last month. The job does not require Senate confirmation, making it easy for Hagin to make a lateral move there.