Maine Gov. Janet Mills is skipping the National Governors Association 2025 summer meeting this weekend in Colorado.

It appears to be the first association meeting that Mills will miss since taking office in 2019. It comes five months after a meeting in February when she clashed with President Donald Trump at the White House, and as she mulls a possible challenge to Republican U.S. Sen. Susan Collins in 2026.

A Mills spokesperson cited her “busy July schedule” for not attending this weekend’s meeting, which will feature U.S. Secretary of Education Linda McMahon, Secretary of Health and Human Services Robert F. Kennedy Jr. and billionaire businessman Mark Cuban, among others.

“The Governor … is an active member of NGA and has good bipartisan relationships with her fellow governors, but because of a busy July schedule, she is unable to take the time to make this year’s summer meeting in Colorado,” Ben Goodman said in a written statement. “She values the NGA and looks forward to continuing to engage with the organization during the remainder of her term.”

Mills made national headlines at the association’s winter meeting in February in Washington, D.C., for her now-infamous confrontation with Trump over transgender athletes.

When Trump threatened to pull federal funding over Maine’s refusal to follow his executive order banning transgender athletes from girl’s sports, Mills calmly retorted, “see you in court,” four words that electrified Democrats nationwide hungry for a leader to oppose Trump and his policies.

That moment led to national media coverage and an appearance by Mills on MSNBC’s “Morning Joe.” It also caught the attention of national Democratic leaders, who have urged the 77-year-old governor nearing the end of her second term to run against Collins, 72, in the 2026 U.S. Senate race.

Mills told the Press Herald in November that she had not ruled it out. As calls for her to run have mounted, Mills has kept the door open, telling the Press Herald in April, “at this moment, I’m not planning to run for another office.”

It’s unclear what role, if any, those two factors may have had in Mills’ decision not to attend. Goodman’s statement did not address questions sent by email and text message Wednesday about whether her experience at the winter meeting or calls for her to challenge Collins factored into her decision.

But Maine’s top Democrat would likely face questioning at the event from the national media about her 2026 plans and her confrontation with Trump earlier this year.

David Farmer, a Democratic strategist who worked for former Gov. John Baldacci, said he didn’t have any insight into why Mills is not attending the conference. But he dismissed the idea that her confrontation with Trump played any role.

“I don’t think there’s any way she’s intimidated by the president or worried about what he or his administration might or might not do in terms of a personal encounter,” Farmer said. “If she is planning a (campaign) launch, that could have something to do with it — being out of state, being tied up, if you’re planning to make an announcement. But that’s speculative. I have no reason to believe that.”

The National Governors Association is a nonpartisan group that holds meetings twice a year, bringing governors across the country together with federal officials, business leaders and philanthropic organizations to discuss the top issues and challenges faced by states, commonwealths and territories.

Former Republican Gov. Paul LePage, during his first term, withdrew Maine as a dues-paying member of the association in 2012, even though he attended some of their meetings. In an interview at the time, LePage said the dues — then about $60,000 annually — were a waste of money.

Mills rejoined the association when she took office in 2019 and then hosted the 2022 summer meeting in Portland — the first time Maine had hosted since 1983.

That meeting, which included a lobster bake at Fort Williams in Cape Elizabeth, came in the wake of the U.S. Supreme Court’s decision to end the national right to an abortion that had existed for nearly 50 years under Roe v. Wade. The nation’s governors were greeted by abortion rights protesters.