ATLANTA — A federal judge refused on Monday to declare Dylann S. Roof, the white supremacist who murdered nine black worshipers at a Charleston, S.C., church, incompetent to face the sentencing phase of his death penalty trial.

The decision, by Judge Richard M. Gergel of Federal District Court, was an unsurprising but crucial echo of a separate ruling in late November, when Judge Gergel said that Mr. Roof did not meet the legal standard to be deemed incompetent. Monday’s ruling, announced after a lengthy closed hearing, was another setback for the court-appointed defense lawyers whom Mr. Roof does not intend to use during the sentencing proceedings.

“After fully considering all of the evidence presented, the court ruled from the bench that Defendant remains competent to stand trial and to self-represent,” the judge wrote in an order, one of a handful of court filings on Mr. Roof’s health that have been made public. The motion that prompted Monday’s hearing was submitted under seal.

Taken together, Judge Gergel’s ruling and Mr. Roof’s apparent resolve to act as his own counsel mean that the sentencing phase will open Wednesday, one day later than scheduled, with an air of uncertainty and a measure of worry. Mr. Roof has said that he will deliver an opening statement — it is not clear what he intends to say — but that he will not call witnesses or present any evidence to the jurors who will decide whether he is sentenced to death or to life in prison.