The party that will control the U.S. House of Representatives for the next two years is currently unknown.

All 435 seats in the lower house of Congress were up for voting this year, and it could be days before final results are in and whether Republicans can retain their slim majority. That would give the party control of Congress and the White House when President-elect Donald Trump is sworn in in January.

Democrats, meanwhile, are hoping that the final votes, coming in a few close elections, will be enough to give them a majority in the House of Representatives.

A party needs 218 seats to take control. As of Wednesday, Republicans have 197 and Democrats have 188.

Here are some of the races that have yet to be announced.

Democrats are closely watching whether five seats in California are critical to winning back the House of Representatives.

Challengers are hoping to defeat incumbent Republicans and turn the seats blue, but early polls show incumbents retaining their seats by narrow margins.

The main races to watch are:

• California's 45th: Incumbent Republican Congresswoman Michelle Steel is currently leading against Democrat Derek Tran with 66% of the reported votes. She has a lead of 5 points.
• California's 27th: Democrat George Whitesides is challenging incumbent Republican Congressman Mike Garcia. With 67% of votes counted, Garcia is ahead by a slim 2.4 points.
• California's 41st: Incumbent Republican Congressman Ken Calvert is running against Democrat Will Rollins. Calvert wins by a narrow margin of 1 point with 60% of the vote counted.
• California's 22nd: Democrat Rudy Salas is challenging incumbent Republican Congressman David Valadao, who currently leads by 10 points. Just over 50% of the votes were counted.
• California's 13th: Incumbent Republican Congressman John Duarte is running against Democrat Adam Gray. With 48% of votes counted, Duarte is leading by almost 3 points.

The two closely watched races in the state currently have margins of less than 2%.

Republican Juan Ciscomani currently leads his Democratic challenger Kirsten Engel by 1.5 points in Arizona's 6th District in the southeastern part of the state. About 60% of the votes have been counted.

In Arizona's 1st District, David Schweikert has a 1.6-point lead over his Democratic challenger Amish Shah with 62% of votes counted.

Schweikert's district covers northeastern Maricopa County, outside Phoenix.

In Maine, incumbent Democratic Congressman Jared Golden is fighting to keep his seat — one of two congressional districts in the state.

Maine's 2nd Congressional District covers most of the state north of Augusta and Portland.

Golden currently leads the race against his Republican challenger Austin Theriault by nearly four points. Around 77% of the votes were counted.

Democrats want to retain a seat in Ohio's 9th Congressional District, which includes Toledo in northern Ohio.

Incumbent Democratic Congresswoman Marcy Kaptur, who has served in Congress since 1983, is leading the race against her Republican challenger Derek Merrin.

Kaptur has a narrow lead of 0.3 points. Around 94% of the votes were counted.