U.S. Senator Jeanne Shaheen on Wednesday became the third Senate Democrat to say she would not seek reelection next year, further complicating her party's hopes of recapturing control of that chamber when President Donald Trump's term reaches its midpoint.

Ms. Shaheen’s retirement will set off a high-stakes fight for an open seat in a state where she has been a leading political figure for decades.

Democratic U.S. Senator Jeanne Shaheen said on Wednesday that she will not seek re-election in 2026, saying it was a difficult decision while there were urgent challenges ahead.