American media reports say it could be days before voters find out who will control Congress after Tuesday's midterm elections.

Democrats and Republicans are vying to secure a majority or 51 seats in the Senate. That includes seats that were not contested. Just a handful remain undecided in an extremely close race.

And in the House of Representatives, all 435 seats were up for grabs. Media projections show the House leaning Republican, but dozens of seats remain undecided.

A report from the Washington Post says logistical issues could delay the final results. It says many people cast absentee ballots or voted by mail.

It also referred to the potential for runoffs or recounts in close contests.

The newspaper says it could be more than a week before all the winners are determined. Other media reports point to the time frame of the US election results in 2020 when it took two weeks to call every state.