UNITED NATIONS — With fast-approaching peace talks in America that are unpopular at home and several ongoing investigations into his conduct — not to mention a near-rebellion in his own party and parliamentary no-confidence motions — Prime Minister Olmert hardly needed more hardship. Yesterday’s disclosure that he is suffering from prostate cancer, however, may have cured, at least temporarily, some of his political ailments.

Some of the Israeli leader’s fiercest political rivals rushed to wish him a full recovery yesterday; the cancer was said to be at an early, curable stage. The three no-confidence motions at the Knesset were quickly voted on and, as expected, defeated.

World leaders, including Secretary of State Rice and a former British prime minister, Tony Blair, called to express their support. Mayor Giuliani, a longtime friend of Mr. Olmert’s and himself a prostate cancer survivor, also called to express his sympathy.

The White House said it did not expect the upcoming Middle East summit in Annapolis, Md., to be postponed.

Still reeling from the turmoil that arose after Mr. Olmert’s predecessor, Ariel Sharon, suffered a stroke last year, Israelis yesterday witnessed a new approach to medical disclosure in the political sphere.

In sharp contrast with past practice, and with no legal requirement to do so, Mr. Olmert, accompanied by two physicians, announced that he has a “microscopic growth” in his prostate. He also disclosed details about a proposed “short surgical procedure” to treat it and answered reporters’ questions at a nationally televised press conference.

Foreign Minister Tzipi Livni will take charge, if necessary, while Mr. Olmert undergoes surgery, and she will become prime minister if he is declared unable to continue to serve. It was not clear, however, what authority would determine such an inability.

According to a report on Israel’s Channel 2 television, the prime minister’s office recently issued a new protocol that assigns a medical doctor as a dedicated caretaker to the country’s premier. Under the new rules, the prime minister and his doctor will make an annual full disclosure of the leader’s medical condition.

The unusual openness of that report and yesterday’s press conference produced an outpouring of sympathy from Israel’s normally cantankerous politicians. After Mr. Olmert’s press conference, legislators from the right and of the left at the Knesset crowded around the prime minister to shake his hand.

“We have many disagreements, but on this issue we are all united,” Benjamin Netanyahu, head of the largest opposition party, Likud, said. In a phone call to Mr. Olmert, Mr. Netanyahu said, he wished him a speedy full recovery. “I have no doubt that he would be able to function even as he undergoes treatment,” said the leader of the Labor Party, Ehud Barak, who serves as Mr. Olmert’s defense minister but who is expected to seek to replace him in the future as prime minister.

Two constant Knesset critics of Mr. Olmert who are also medical doctors were gracious, as well.

“Olmert should not resign because of the cancer, but despite the cancer,” Dr. Aryeh Eldad of the far right National Union Party said, according to Ynet. Dr. Eldad added that the prime minister’s cancer should have no effect on his ability to lead.

“The way he faced the public was courageous and showed public responsibility,” Dr. Ahmad Tibi of the far left Arab Renewal Party said.

Turmoil in Mr. Olmert’s own party, Kadima, is also expected to die down for a while, the Web site of the Israeli newspaper Ma’ariv reported. Yesterday’s news guaranteed a short reprieve for the prime minister from leaders, including Ms. Livni, who have tried to unseat the Kadima leader.

“After the Sharon trauma, no one would challenge a sitting cancer-stricken prime minister,” an unidentified party source was quoted as saying.

Mr. Olmert’s challenges as a leader of a country at war have not disappeared, however. The government’s legal adviser, Menachem Mazuz, called for the suspension of an earlier Cabinet decision to disrupt the electricity supply to Gaza, where militants continued to launch rockets across the border into Israel. More legal deliberation was in order before implementing the policy, Mr. Mazuz said. Secretary-General Ban yesterday issued a statement saying he “believes strongly that punitive measures taken by Israel which harm the well-being of the entire population of the Gaza Strip are unacceptable.”

Limiting fuel and electric supplies, he said, would “deepen the humanitarian distress of the 1.4 million residents of Gaza.” The U.N. leader also strongly condemned the rocket fire from Gaza. Ms. Rice is expected to visit Israel next week to firm up her plans to convene Arab and Israeli leaders at Annapolis, either in late November or early December.

The secretary “has not announced a date for the conference,” the White House press secretary, Dana Perino, said, adding that from press reports on Mr. Olmert’s condition, “it didn’t seem to me that there would be any reason to delay” the Annapolis summit.