WASHINGTON — The Obama administration, contemplating the possible retirement of U.S. Supreme Court Justice John Paul Stevens, is focusing on three candidates to succeed him, a White House official familiar with the deliberations said.

The group includes U.S. Solicitor General Elena Kagan and federal appellate judges Diane Wood and Merrick Garland, the person said, speaking on the condition of anonymity.

Stevens, who will turn 90 on April 20, told The New York Times in an Friday interview that he will decide soon whether he will step down. “The president and the Senate need plenty of time to fill a vacancy,” Stevens told the newspaper.

Stevens hasn’t communicated his intentions to the White House one way or another, according the person familiar with the deliberations. President Obama hasn’t begun discussing particular candidates with aides, and the list of leading candidates could change in the coming weeks, the person said.

“We’ll be prepared if a vacancy arises, but there’s no vacancy on the court, and there’s no short list awaiting a potential vacancy,” White House spokesman Ben LaBolt said in an e-mail.

White House officials expect that any retirement announcement would come after the high court’s last argument of its current term, on April 28, the person said. The administration is preparing to move quickly with a nomination, the person said.

Kagan, 49, and Wood, 59, interviewed with Obama last year before he appointed Sonia Sotomayor to succeed David Souter on the high court, according to a different White House official. Garland, 57, was one of nine candidates the White House considered for that vacancy, though he didn’t meet with Obama.

Kagan is the first woman to serve as solicitor general, the federal government’s top Supreme Court advocate. She took that post after serving as the first female dean of Harvard Law School, her alma mater.

Kagan won praise from conservatives and liberals alike for smoothing over the ideological tensions that plagued Harvard Law School before she became dean in 2003.

Still, her nomination to become solicitor general was divisive. She won confirmation on a 61-31 vote, with some Republicans voicing concern about her lack of courtroom experience and her opposition to on-campus military recruiting at Harvard.

Wood, a judge on the 7th U.S. Circuit Court of Appeals in Chicago since 1995, has developed a reputation there as an intellectual jurist willing to take on her more conservative colleagues Richard Posner and Frank Easterbrook.

A graduate of the University of Texas School of Law, Wood is an antitrust expert, serving as deputy assistant attorney general under President Clinton.

Garland, a judge on the U.S. Court of Appeals for the D.C. Circuit, is perhaps the most conservative of the trio, often siding with the government on criminal questions.

A Harvard Law School graduate, he worked in the Clinton administration’s Justice Department, overseeing the Oklahoma City bombing investigation and the successful prosecution of Timothy McVeigh.

For last year’s vacancy, officials also considered Homeland Security Secretary Janet Napolitano, Democratic Gov. Jennifer Granholm of Michigan and then-Chief Justice Leah Ward Sears of the Georgia Supreme Court. Martha Minow, who succeeded Kagan as Harvard Law School dean, is also a possibility for the Stevens seat, the first White House official said.