The United States is set to learn the outcomes of its closely watched midterm elections on Tuesday night, with the first results anticipated as polls begin to close.

This election is significant as all 435 seats in the US House of Representatives and 35 Senate seats are contested. Democrats are vying to gain control of both chambers, currently held by President Donald Trump's Republican Party.

The initial vote counts are expected to emerge shortly after polls shut, starting at 6 p.m. Eastern Standard Time (23:00 GMT) on the East Coast. However, officials caution that these early figures do not immediately signal a declared winner. Election administrators will be processing ballots, and news organizations will analyze the data to project outcomes.

Given the potentially tight margins in many races, it may take hours, or even days, to definitively determine which party will control Congress. The final determination of whether Republicans retain their majority or Democrats achieve control in either the House or Senate could be delayed.

Polls will close progressively across the country. The earliest closures are in parts of Indiana and Kentucky at 6 p.m. EST. Subsequent closures will occur throughout the evening, with the last polls shutting at 9 p.m. EST (02:00 GMT on Wednesday) in states like Arizona, Colorado, Iowa, and New York, among others.

Factors such as the processing of mail-in ballots, which are extracted from envelopes at centers like the one in Los Angeles County, can contribute to the time it takes to finalize results. The complexity of vote counting and verification processes across different states means that a swift resolution is not always guaranteed.

Historically, midterm elections often see the president's party face challenges, and this election cycle is no exception, with significant implications for President Trump's legislative agenda and political standing.

As vote counts are released and analyzed, the nation and the world will be watching to see how the balance of power in Washington shifts, with the final picture potentially taking longer to emerge than many anticipate.