WASHINGTON - The government is expanding its definition of rape, including men for the first time when counting the number of victims, the Obama administration announced Friday.

The expansion, which supporters say is long overdue, is important because policymakers and lawmakers use crime statistics to allocate resources for prevention and victim assistance.

In a press briefing, senior White House adviser Valerie Jarrett called the change a "very, very important step" because it counts men and because it includes rapes of women other than by physical force.

Since 1929, the FBI has defined rape as the carnal knowledge of a female, forcibly and against her will. The revised definition covers any gender of victim or attacker and includes instances in which the victim is incapable of giving consent due to the influence of drugs or alcohol or because of age. Physical resistance is not required.

The new definition will not change federal or state laws and will not alter charges or prosecutions.

"Rape is a devastating crime, and we can't solve it unless we know the full extent of it," Vice President Joe Biden said in a statement.

Biden, author of the Violence Against Women Act when he was in the Senate, said the new definition is a victory for women and men "whose suffering has gone unaccounted for over 80 years."

According to government data, one in five women and one in 71 men are rape victims.