WASHINGTON — The Justice Department on Friday revived an Obama-era office that was created to make legal aid accessible to citizens who cannot afford it, more than three years after it was essentially shuttered under the Trump administration.

Attorney General Merrick B. Garland said the restoration of the Office for Access to Justice was part of the department’s mission to deliver on its promise to ensure equal justice.

When it was created under the Obama administration in 2010, the office’s stated mission was to “deliver outcomes that are fair and accessible to all, irrespective of wealth and status.” And it sought to “increase access to counsel and legal assistance” for people who could not afford legal representation.

“There can be no equal justice without equal access to justice,” Mr. Garland said in a statement. “And because we do not yet have equal access to justice in America, the task before us is urgent.”

Under Jeff Sessions, former President Donald J. Trump’s first attorney general, the Justice Department diverted funding and staff from the office, leaving it defunct. Mr. Sessions could not officially close it without first notifying Congress.

Mr. Garland had signaled during an oversight hearing on Wednesday before the Senate Judiciary Committee that he intended to restore the office.

“We have determined that we should stand up once again, an independent, within the department, Office of Access to Justice,” Mr. Garland told Senator Chris Coons, Democrat of Delaware.

He noted that the Justice Department had requested funding for the office in its fiscal year 2022 budget request. It asked for $6 million, up from zero the two previous fiscal years.

This spring, President Biden, in an executive order, gave the Justice Department until mid-September to devise a budget and staffing plan to expand legal services to indigent defendants, a vast percentage of whom receive inadequate or no legal services in civil litigation.

Mr. Garland said the reopening of the office was the first step in his plan to restore and expand the federal government’s efforts to ensure that financially strapped Americans had access to legal aid.

He asked Deputy Attorney General Lisa O. Monaco and Associate Attorney General Vanita Gupta to work on the plan with input from stakeholders inside and outside the Justice Department.

The plan they created included input from civil legal aid providers, public defenders, pro bono lawyers, bar associations, data scientists and advocates for environmental justice, economic justice and immigration reform.