U.S. House Speaker Nancy Pelosi has announced that she is seeking to be reelected as speaker for the U.S. House of Representatives.

"I am writing to request your support to be reelected as Speaker," Pelosi said in a letter sent to her colleagues on Friday morning.

Pelosi, 80, won reelection to the U.S. House in California's 12th Congressional District in this year's general elections, in which all the 435 seats of the chamber were contested.

Democrats are expected to keep control of the lower chamber, but their majority has been forecast to be narrower.

In the Senate, based on races that have been called so far, Republicans and Democrats are deadlocked at 48 seats each.

Republican leaders said on Friday that it is still unclear which party will control the 100-seat upper chamber.