The US Supreme Court has ruled that university and college admissions policies that consider applicants' race are unconstitutional.

The court on Thursday struck down the affirmative action pursued for decades by many universities and colleges to achieve diversity in their student bodies.

The plaintiff had claimed admissions programs at educational institutions, such as Harvard University, have given preferential treatment to Black and Hispanic applicants and discriminated against their Asian and White peers.

The court's judgement overturned its rulings dating back to 1978 that it is constitutional for educational institutions to use race as a factor to consider in their admissions process.

College administrators across the US have tried for decades to reflect the diversity of society on campus. They have used race as a factor in admitting new students as part of a program known as affirmative action. But on Thursday, justices on the Supreme Court struck down such policies as unconstitutional.

A group called Students for Fair Admissions filed lawsuits against Harvard University and the University of North Carolina. They claim the schools admitted Black and Hispanic students who were "unqualified" and "discriminated" against white and Asian-American applicants.

The justices decided the programs were not consistent with the Constitution's Equal Protection Clause, which guards against discrimination. A majority agreed the admissions policies lack "measurable objectives" warranting the use of race.

Harvard University posted an open letter saying it will comply with the decision. However, it said learning depends on a community "comprising people of many backgrounds" and perspectives.

President Joe Biden criticized the ruling, saying the court walked away from decades of precedent.

Biden said, "We need to keep an open door of opportunities. We need to remember that diversity is our strength. We have to find a way forward."

Officials with the Department of Justice and Department of Education plan to provide college administrators with further guidance in the coming weeks. They will advise them on what practices and programs are still lawful.