Stephen K. Bannon, a longtime adviser to President Trump, pleaded guilty on Tuesday in Manhattan criminal court to a single count of defrauding donors who sought to help build a wall at the southern border.

Mr. Bannon’s plea deal stipulates that he will be given a three-year conditional discharge, meaning he will receive no prison time if he does not reoffend.

He had faced five felony counts, including money laundering and conspiracy charges, and faced a maximum sentence of five to 15 years on the most serious charge.

This is a developing story and will be updated.