The University of Minnesota is going public with a campaign to raise $4 billion for scholarships, faculty research and other projects by the year 2021.

It's the largest philanthropic effort ever undertaken by the university, said Kathy Schmidlkofer, president of the University of Minnesota Foundation.

The campaign, which was formally announced Friday, already has raised $2.5 billion, nearly 63 percent of its goal, officials say. But they waited until now to launch the public phase of the campaign, which has been quietly underway since 2011.

The university set an ambitious goal to raise $1 billion for scholarships and other student aid; $2 billion for faculty and research, and $1 billion for a broad range of university initiatives.

Some of the largest individual donations — including $25 million gifts from the Masonic Charities and Land O'Lakes in 2014 — already have been announced. But collectively, they're all part of a single campaign, called Driven, to generate public support for the university's broad-ranging missions, from "a world-class student experience" to advances in medicine, environmental science and other top priorities, the U announced Friday.

"What we're trying to achieve is to keep our status, obviously, as one of the major public institutions in the country," said Nancy Lindahl of Deephaven, who co-chairs the campaign with her husband, John. The couple, both alumni and longtime donors, have been traveling the country raising money for the U.

Officials say it's typical for large fundraising campaigns at universities to operate under the radar before going public, often when half the funds are in hand. In this case, the university waited six years to break the news at Friday's Board of Regents meeting.

"I think it's an opportunity to generate additional investment in excellence at the U," said President Eric Kaler, who began the campaign the year he took office. "We're just increasing our efforts in this phase."

The campaign is not designed to replace state funding or address tuition costs, officials say. But so far, it has raised enough money to fund 700 new undergraduate scholarships, with a goal of creating 1,000, said Sarah Youngerman, a spokeswoman for the campaign.

Half the $4 billion goal is earmarked to support research in such key areas as clean water, robotics, neurosciences, addiction and aging, as well as new endowed chairs and professorships, Youngerman said. She said all five campuses would benefit from the donations, as will university-owned facilities such as the Minnesota Landscape Arboretum, the Weisman Art Museum and the Bell Museum of Natural History.

This is the U's first official fundraising campaign since 2003, when the university raised $1.6 billion in four years.