A school district serving two suburban communities in New Jersey has agreed to expand access to Advanced Placement classes and other higher learning opportunities to African American students, following an investigation by the U.S. Department of Education.

The announcement comes just weeks after Education Secretary Arne Duncan warned that his agency will investigate districts and states that are not providing poor and minority students with access to strong teachers, demanding coursework and facilities that their white peers receive.

After opening a review of the New Jersey regional school district that serves South Orange and Maplewood in May 2013, federal officials found significant disparities in academic opportunities between white and African American students enrolled in the suburban system.

Of the 6,622 students who attended the district’s nine schools in 2013, 38 percent were African American and 49 percent were white.

But black students occupied just 19 percent of the seats in Advanced Placement courses, and were underrepresented in other programs for advanced learners at the elementary and middle school levels, investigators said.

Before the federal review was completed, district officials agreed to take specific actions to make sure it is providing an equal opportunity for black students to take AP courses, honors classes and participate in other enrichment programs, according to officials at the U.S. Department of Education.

The school district has committed to:

•Work with an expert consultant, survey students, parents and staff and assess current programs and courses to identify any potential barriers

•Consider expanding criteria to determine eligibility and selection for enrollment

•Expand student, parent, and community outreach about available courses and programs

•Improve academic counseling services at the middle school and high school levels

•Train district and school site administrators and personnel in elementary and middle school math enrichment programs and advanced courses.

Federal data show deep disparities in educational resources for poor and minority students nationwide.

Of schools serving the highest percentages of black and Latino students, just 66 percent and 74 percent offer chemistry and Algebra 2, respectively. Students of color are more likely to attend schools with lower-quality facilities such as temporary, portable classrooms, than white students. And they are more likely to be taught by educators who do not meet state certification requirements.

Duncan said earlier this month that his agency would be a “watchdog” to correct inequities in the nation’s schools.