President Obama announced Saturday that he seeks $4 billion from Congress to dramatically increase the number of children who have access to computer science classes in school, a move he said is necessary to ensure that students are competitive in a job market that rewards technological know-how.

“In the new economy, computer science isn’t an optional skill — it’s a basic skill, right along with the three ‘R’s,’ ” Obama said in his weekly radio address.

The president had mentioned the need for broader access to computer science classes in his State of the Union address earlier this month, but had not provided much in the way of details until Saturday’s announcement.

If Congress approves the president’s budget request, the $4 billion would be doled out over a period of three years to any state that applies for the funds and has a well-designed plan to expand access to computer science courses, especially for girls and minorities.

The administration also is seeking an additional $100 million to fund a competitive grant program for school districts with ambitious plans to reach more students, especially those who have been underrepresented in computer science classes.

Just about 25 percent of the nation’s K-12 schools offer computer science courses, according to the White House, and 22 states do not allow computer science courses to count toward high school graduation requirements.

Fewer than 15 percent of high schools offered Advanced Placement Computer Science in 2015, and the demographics of those AP classes were not representative of the student population. Just 22 percent of students who took the AP exam in 2015 were girls, and 13 percent were black or Latino.

Administration officials said they will dedicate approximately $135 million in existing funds, mostly from the National Science Foundation, to help train thousands of teachers and design new instructional materials for computer science classes.

White House officials described it as the largest federal effort to date to expand computer science courses, and an attempt to accelerate efforts already underway in many cities and states. They called on tech companies and philanthropists to get behind the initiative.

“It’s really a call for all hands on deck,” U.S. Chief Technology Officer Megan Smith told reporters Friday.