President Lawrence H. Summers unveiled a $14 million boost to financial aid across the University yesterday, as the centerpiece of an aggressive plan to make graduate education at Harvard more affordable.

Along with a low-interest loan partnership with Citibank, the program is Summers’ long awaited answer to a pledge made in his inaugural address to make it possible for students to attend any of Harvard’s graduate schools regardless of financial need.

But in a press conference yesterday, Summers stressed that the initiatives— which target students interested in a career in public service—are only a first step.

Summers said conversations with students and administrators at Harvard’s various schools alerted him to the fact that Harvard did not do enough to assist students interested in pursuing a career in public service.

“I was very struck by the fact that there was substantially more financial aid available to you if you wanted to come to Harvard to be an investment banker or a lawyer than if you wanted to be a scientist or a teacher,” Summers said.

Starting in September, a new scholarship known as the Presidential Scholars program will dole out $14 million over three years in grants to students considering careers in public service or research.

The funds would go to all of Harvard’s graduate and professional schools except for the Law School and the Business School. Those schools already have generous aid programs, Summers explained, and their graduates typically earn larger salaries and have less trouble repaying student loans.

Graduate students in the natural sciences, who generally receive more federal aid, will also not be elligible for the scholarships.

“There’s a very full package of support that’s already provided to students in the sciences but that’s not available to students in the humanities and social sciences,” Summers said.

Roughly 200 to 300 students are expected to receive the new grants during the program’s first three years.

Each school’s admissions and financial aid office will develop its own system for selecting scholarship recipients, Summers said.

While some will use need as the primary criteria, others will base their decisions on the candidates’ academic merits.

The second part of the plan unveiled yesterday will create a new low-interest loan program.

Graduate students across the University will now be eligible for the Harvard Educational Loan Program (HELP), a partnership with Citibank’s Student Loan Corporation offering student loans at below-market rates of 4 1/8%.

Unlike most other loans, these loans will be available to international students as well as domestic students, a fact that Summers said would particularly benefit the School of Public Health and the Kennedy School, which draw a large number of students from foreign countries.