House Democratic leader Nancy Pelosi said she has “overwhelming support” among fellow Democrats to become the next House speaker.
Ms Pelosi said: “I intend to win the speakership with Democratic votes.”
Ms Pelosi said she thought she was the best person for the job and that any Democrat who disagrees should run against her.
Disgruntled Democrats claim they have 17 names on a letter opposing Ms Pelosi’s leadership.
Ms Pelosi is dismissing that challenge, and she asks reporters: “Have you seen the letter?”
Democrats seeking to block Ms Pelosi argue it is time to give younger Democrats a chance to rise to high-level posts.
The holder of the post is second in line to the presidency after the vice-president.
The Democrats took back control of the House in this year’s midterm elections but President Donald Trump’s Republicans maintain control of the Senate.
