A New York City prosecutor's office joined the U.S. Justice Department on Thursday in a $79 million effort to help police in 20 U.S. states process untested rape kits that can provide physical evidence to help solve sexual assaults.

Manhattan District Attorney Cyrus Vance said his office awarded $38 million in grants toward the initiative, saying that collecting forensic evidence linked to sex assaults across the country could help solve similar unsolved crimes in New York.

The money, which will be allocated alongside $41 million from federal prosecutors, will be used to test medical evidence collected after sexual assaults in jurisdictions with the largest backlogs across the United States, as well as to analyze why the kits have remained untested.

"You're as likely to find the rapist from Times Square in Ogden, Utah, as you are in Times Square. You're as likely to find him in Oregon or Mississippi as you are in Times Square," said Vice President Joe Biden, who joined Vance for Thursday's announcement. "In turn, you bring closure for the woman in New York, or the man."

The announcement expanded on the White House's Sexual Assault Kit Initiative, launched earlier this year, which promised to tackle the estimated backlog of 400,000 untested rape kits in crime labs across the country.

New York City eliminated its backlog of 17,000 rape kits in 2003 and then adopted a policy of testing every kit.

"Tackling the national rape kit backlog means addressing a women's and human rights issue that has been ignored for far too long. We are refusing to accept that some criminal justice problems are just too big – too ingrained, too controversial, too expensive – to solve," Vance said.

Biden, who could become a Democratic candidate in the 2016 presidential election campaign, has taken up the sex assault issue in the past, calling rape on campus an "epidemic" and championing the Violence Against Women Act.

(Reporting by Katie Reilly; Editing by Scott Malone and Peter Cooney)