When Gov. Kim Reynolds interviews nearly the entire Republican presidential field at the Iowa State Fair next month in a series of one-on-one chats, there will be one especially notable absence: former President Donald J. Trump, the clear favorite in the race.

Ms Reynold’s office on Tuesday released a list of participants for the interview series that did not include Mr Trump. The former president, who has expressed anger at Ms Reynolds for not endorsing him, declined an invitation to participate.

While it’s traditional for Iowa governors to stay out of presidential primaries, Trump’s team believes Reynolds is neutral in name only, pointing to a series of events he has attended with Florida Gov. Ron DeSantis, Trump’s main rival.

Trump appears intent on prolonging his public feud with the popular Ms. Reynolds, which has angered and puzzled conservatives in the state. Even a Republican State Senator turned around his endorsement by Mr. Trump of Mr. DeSantis after the dispute. Trump, confident in his advantage over the rest of the field, has shown a broader willingness to skip major primary events, which could include the first Republican presidential debate in late August, which he has not committed to attend.

The interviews with Ms. Reynolds, called “Fair-Side Chats,” will take place August 10-18 at JR’s SouthPork Ranch at the Iowa State Fairgrounds in Des Moines. The Iowa State Fair, famous for its fried food sticks and life-size butter cow sculpture, is a crucial opportunity for presidential hopefuls to mingle with voters ahead of the state caucuses in January.

Steven Cheung, a Trump spokesman, said the former president planned to attend the state fair, but not the interview with Reynolds.

“President Trump looks forward to interacting with tens of thousands of Iowans at the fair in an open and unfiltered environment,” Cheung said in a statement.

Of the other leading Republican presidential candidates, only former New Jersey Gov. Chris Christie will not participate in an interview with Ms. Reynolds. Mr. Christie’s campaign has saying is choosing to compete in New Hampshire and South Carolina, the other early nominees, over Iowa.

Otherwise, the remaining top candidates, including Senator Tim Scott of South Carolina, as well as long shots like businessman Perry Johnson, agreed to attend.

“The Iowa State Fair showcases the best of Iowa, from our people to our culture to our wonderful agricultural industry, and is the perfect place to chat with candidates,” Ms. Reynolds said in a statement.

Meanwhile, Mr. DeSantis seems to enthusiastically nurture his relationship with Ms. Reynolds. tell reporters at a state campaign stop this month that he would consider her as a running mate, should he win the nomination.

“I mean, she’s one of the top public servants in the United States,” she said.

recent polls show DeSantis ranks second in Iowa, a state many of his allies say he must win, behind Trump by about 30 percentage points. The governor is scheduled to begin a bus tour of the Des Moines area on Thursday before speaking at a dinner for the Iowa Republican Party on Friday. Almost every other candidate, including Mr. Trump, is also set to talk in the dinner