Democrat Mary Peltola's narrow lead over Republican Senator Dan Sullivan in Alaska's uncalled US Senate race shrank to 3,975 votes in the latest count, as a judge rejected her campaign's attempt to obtain records identifying voters whose absentee ballots were rejected.

The Alaska Division of Elections' official summary showed Peltola with 121,487 first-choice votes, or 48.73 per cent, against 117,512 votes, or 47.13 per cent, for Sullivan. The latest batch of results added 5,612 early, absentee and Election Day ballots to the count and cut Peltola's advantage from 4,250 votes to 3,975. The Associated Press estimates that about 86 per cent of the expected vote has now been counted, with roughly 14 per cent still to come.

Neither candidate has reached the 50 per cent of first-choice votes needed to win outright under Alaska's ranked-choice voting system, so the race is heading for a ranked-choice tabulation on 18 November. Two other candidates remain in the count: Daniel J. Sullivan Jr., a retired teacher from Petersburg who shares the incumbent's name, has 4,100 votes, while Gerald Heikes has 5,426. The state's target date for certifying the results is 25 November.

Judge refuses rejected-ballot list

Superior Court Judge Thomas Matthews ruled on Wednesday that the Peltola campaign will not receive a list of absentee voters whose ballots were rejected, or the reasons for the rejections. The campaign had gone to court seeking the records during the ongoing count, but the judge found the request was not reasonable in the middle of the count, saying the Division of Elections was in the middle of counting ballots and faced deadlines it must meet.

The ruling came as the count itself continued. The next results release is expected on Friday 13 November, the deadline for most mailed ballots sent from inside the United States to arrive. Ballots mailed from overseas can still arrive until 18 November, the same day the Division of Elections is due to run the ranked-choice tabulation.

America's last uncalled Senate race

Alaska is the only Senate race in the country still uncalled, more than a week after the 3 November midterm election. The overall Senate majority has already been decided, with Democrats winning control of the chamber, but the Alaska result will decide the final margin. Peltola led by only 636 votes on election night, and her advantage has grown and shrunk with each batch of ballots since.

President Donald Trump weighed in on the race on Saturday, claiming on social media that Sullivan had won by a large margin, but no news organisation or election authority has declared a winner, and Peltola has moved further ahead since that post. With the margin smaller than the votes cast for the other Sullivan on the ballot, the ranked-choice count on 18 November is likely to decide who takes the seat.