WASHINGTON — In a second trail-blazing pick for the nation’s top law enforcement officer, President Obama intends to nominate a federal prosecutor in New York to become the next attorney general and the first black woman to lead the Justice Department.

Obama’s spokesman said Friday that he will announce his selection of Loretta Lynch from the White House on Saturday. If confirmed by the Senate, she would replace Eric Holder, who announced his resignation in September after serving as the nation’s first black attorney general.

Lynch, 55, is the U.S. attorney for Eastern New York, which covers Brooklyn, Queens, Staten Island and Long Island, a position she also held under President Clinton.

“Ms. Lynch is a strong, independent prosecutor who has twice led one of the most important U.S. attorney’s offices in the country,” Obama press secretary Josh Earnest said in a statement.

Obama had planned to wait until after a trip to Asia next week to announce the choice but then moved up the decision after news organizations began reporting that she was his choice.

The White House said Obama is leaving it up to Senate leadership to determine whether she should be confirmed this year while Democrats are in control or next year after Republicans take over. But the White House said their hope is she will be confirmed as soon as possible. Senate Republican leader Mitch McConnell says her nomination should be taken up in the new year.

Democrats on Capitol Hill have told the White House it would be difficult to win confirmation for a new attorney general during the lame-duck session of Congress beginning next week, especially considering all the other competing priorities they face before relinquishing power to Republicans.

It’s unusual for Obama to pick someone he doesn’t know well for such a sensitive administration post. But at a time when Obama is under political fire, Lynch’s distance from the president could be an asset in the confirmation process. Another candidate Obama asked to consider the job, former White House counsel Kathy Ruemmler, asked not to be nominated out of concern her close relationship to Obama could lead to a difficult confirmation effort.

Republicans are promising tough scrutiny after years of battles with Holder. He is close to Lynch and appointed her as chair of a committee that advises him on policy. Since Lynch is unfamiliar to many on Capitol Hill, senators will have to get up to speed on her record quickly.