Prime Minister Benjamin Netanyahu of Israel will officially and publicly appeal to President Obama in the coming days for the release of Jonathan Jay Pollard, the American serving a life term in a North Carolina prison for spying for Israel, Mr. Netanyahu’s office announced Tuesday.

A public request, as opposed to Israel’s discreet efforts in the past, would constitute a new approach in the campaign for Mr. Pollard’s release and an additional twist in a long and painful chapter in Israeli-American relations.

Mr. Pollard, a former United States Navy intelligence analyst who pleaded guilty to spying for Israel, a close ally, has already spent 25 years in prison. Many American law enforcement and intelligence officials have opposed granting him clemency.

Mr. Pollard’s supporters argue that his life sentence was disproportionate, that the information he passed to Israel can no longer harm American national security and that his health is failing.

Mr. Netanyahu has tried in the past to trade Mr. Pollard for pliancy in Middle East peace negotiations, in the hope that the release of the spy would appease conservatives in the Israeli government. Mr. Netanyahu made Mr. Pollard’s case a bargaining point with the Palestinians at the Wye Plantation talks in 1998.

Most recently, in September, Israeli officials tried to float a deal in which they would extend a temporary moratorium on settlement construction in the West Bank, a Palestinian condition for negotiations, in exchange for the release of Mr. Pollard.

In Washington, Obama administration officials indicated that Mr. Pollard’s release was unlikely.

For one thing, the Central Intelligence Agency has fought his release for years; the agency views him as a spy who deserves his life sentence, arguing the release of Mr. Pollard would send a bad message about how the United States viewed people who traded in American secrets.

Beyond that, Mr. Netanyahu, who has consistently resisted attempts by the Obama administration to extend a settlement freeze to aid peace talks with the Palestinians, is not exactly in good favor with the Obama administration right now.

White House officials said Tuesday that they had not received Israel’s official request yet. But the White House press secretary, Robert Gibbs, indicated that when the request did come, the answer would be no. “I am not aware that that’s something that the president is looking at doing,” he said.

Mr. Pollard recently made a personal request for a public appeal for his release. The request was relayed in writing by Mr. Pollard’s wife, Esther, who met with Mr. Netanyahu on Monday. The prime minister’s office said he made the decision after a series of talks and contacts with senior administration officials in recent months.

Israel’s willingness to go public represents a turnaround in what has been a complicated relationship. At first, Israel disowned Mr. Pollard, saying that he was an actor in a rogue operation. But he was granted Israeli citizenship in 1995, and Mr. Netanyahu, during his first term in office in the late 1990s, officially recognized Mr. Pollard as an Israeli agent.

“I intend to continue acting with determination for Pollard’s release,” Mr. Netanyahu said in a statement on Tuesday, “both because of the state of Israel’s moral obligation to him and so that he might live with his family and restore himself to health after his prolonged incarceration.”

Lawrence J. Korb, who was assistant secretary of defense in the Reagan administration, and who supports clemency for Mr. Pollard, accompanied Mrs. Pollard in the meeting with Mr. Netanyahu on Monday.

Mr. Korb told reporters here on Tuesday that he had told the prime minister that to “get the ball rolling,” Mr. Netanyahu should ask for Mr. Pollard’s release publicly and “not as a quid pro quo, but as a matter of justice.”

In addition, Mr. Korb said, Israel should acknowledge that it was wrong to have recruited a spy against its closest ally and should say that it is willing to cooperate fully with the Americans to bring the chapter to a close.

That, he suggested, may help some supporters of Mr. Pollard in the United States to come forward, including those who may otherwise fear being seen as disregarding national security.

Mr. Pollard, who worked for the Navy as a civilian intelligence analyst, began spying for Israel after he approached an Israeli officer in the spring of 1984. He was arrested 18 months later.