The US Department of Justice, questioning Harvard University's use of race as a criterion in its admissions process, on Thursday supported Asian-American applicants suing the Ivy League school for discrimination.

By filing a statement of interest, the department supported the claim made by the plaintiff, Students for Fair Admissions (SFFA), that Harvard has been intentionally and systematically discriminating against Asian Americans by elevating the standard for their admission and limiting the number who get accepted.

The statement of interest said the university "has failed to carry its demanding burden to show that its use of race does not inflict unlawful racial discrimination on Asian Americans".

With some of its Asian-American members denied admission to Harvard, the student organization filed the lawsuit against Harvard in US Distict Court in Boston, Massachusetts in 2014.

"The record evidence demonstrates that Harvard's race-based admissions process significantly disadvantages Asian-American applicants compared to applicants of other racial groups," the Justice Department wrote in the filling.

The filing said that Harvard "uses a vague 'personal rating' that harms Asian-American applicants' chances for admission and may be infected with racial bias; engages in unlawful racial balancing; and has never seriously considered race-neutral alternatives in its more than 45 years of using race to make admissions decisions."

The rating system has resulted in Asian-American applicants on average scoring lower than white applicants, which was counter to the diversity goals of Harvard, the plaintiffs said.

Associated with Harvard's diversity target was its efforts to monitor and manipulate the racial makeup of the incoming class, claimed the Justice Department. Asian Americans, for example, comprised 20 percent of admissions in two consecutive years.

Such practices, defined by the Justice Department as attempts to "racially balance" the makeup of a student body, are "patently unconstitutional" the filing said.

"No American should be denied admission to school because of their race. As a recipient of taxpayer dollars, Harvard has a responsibility to conduct its admissions policy without racial discrimination by using meaningful admissions criteria that meet lawful requirements," Attorney General Jeff Sessions said in a statement.

"Students for Fair Admissions is gratified that, after careful analysis of the evidence submitted in this case, the US Department of Justice has concluded Harvard's admissions policies are in violation of our nation's civil rights laws," Edward Blum, SFFA president, said in a release.

"We look forward to having the gravely troubling evidence that Harvard continues to keep redacted disclosed to the American public in the near future," Blum said.

Harvard on Thursday responded by saying it was "deeply disappointed" by the Justice Department's decision and criticized the arguments as "misleading and hollow".

"This decision is not surprising given the highly irregular investigation the DOJ has engaged in thus far, and its recent action to repeal Obama-era guidelines on the consideration of race in admissions," Harvard said in a statement.

In July, the Education and Justice departments announced that they were reversing seven guidelines from when Barack Obama was president that encouraged schools to achieve diversity using race.

The announcement was considered a signal for the department's decision to side with the plaintiffs in the Harvard case.

The case has drawn wide attention to how race and the pursuit of diversity factor into universities' admissions processes but also is seen as a reading on the Trump administration's attitude toward affirmative action.

In support of Harvard, a group of students and alumni filed a brief in July in which they condemned the lawsuit as an attempt to "dismantle efforts to create a racially diverse and inclusive student body through college admissions".

Arguing that diverse communities are vital to the learning experience of every student, Harvard said it "does not discriminate against applicants from any group and will continue to vigorously defend the legal right of every college and university to consider race as one factor among many in college admissions, which the Supreme Court has consistently upheld for more than 40 years".

Harvard also got support from 16 other US universities, which also filed a brief last month, echoing Harvard's stance that diversity of the student body is essential to achieving educational missions.

The case is scheduled to go to trial in October.