JERUSALEM -- After a week of intense diplomatic meetings with Palestinian leaders, Secretary of State John Kerry is counting on an Israeli government decision to release long-serving Palestinian prisoners as the crucial remaining step for his promised resumption of Middle East peace talks, officials said Saturday.
A senior Israeli minister, Yuval Steinitz, told Israel Radio, "There will be some release of prisoners," including some he described as "heavyweight."
But officials who have been briefed on the negotiations, speaking on the condition of anonymity because they were not authorized to do otherwise, said the prisoner release -- and the larger agreement to resume talks -- depends on a vote in the coming days by an Israeli leadership that has been bitterly divided over the issue.
In announcing Friday that Israelis and Palestinians had established "a basis" for resuming direct peace negotiations, Mr. Kerry included a caveat. "If everything goes as expected," he said, chief negotiators for each side will convene in Washington "within a week or so."
That, apparently, was a reference to the prisoner deal, negotiated in a series of hurried telephone calls with Prime Minister Benjamin Netanyahu of Israel on Friday evening as Mr. Kerry was eager to get home but determined not to leave empty-handed after six visits in four months.
It remained unclear on Saturday how many Palestinian prisoners were to be released and when, though it was unlikely to happen before the first meeting in Washington. It was also not clear whether the vote required was of Mr. Netanyahu's full cabinet or a smaller circle of top ministers known as the security cabinet, both of which meet regularly on Sundays; Mr. Netanyahu has secured the support of several key ministers.
"I don't want to give numbers," Mr. Steinitz, the minister for strategic affairs and a close ally of Mr. Netanyahu's, said on Israel Radio on Saturday. "But there will be heavyweight prisoners who have been in jail for tens of years."
One of three main Palestinian demands for resuming talks has been the release of about a hundred Palestinians who have been jailed since before the signing of the Oslo peace accords in 1993. The other demands are using the 1967 prewar borders as the basis for negotiations, and freezing Israeli settlement activity in the West Bank.
The formula Mr. Kerry negotiated, officials said, involves the United States' making a declaration about the borders and settlements, and recognition of Israel as a Jewish state, that Mr. Netanyahu and President Mahmoud Abbas of the Palestinian Authority can distance themselves from while still negotiating.
The Palestinian political leadership expressed dissatisfaction with that formula on Thursday, but when it became clear that Israel would not budge further, the focus on Friday turned back to prisoners, an issue with profound emotional resonance on both sides. Palestinians consider the men in Israel's jails, particularly those serving since before Oslo, prisoners of war. Israelis call them terrorists. Some have been convicted of multiple murders, and the families of their victims have already made passionate public appeals against the release.
"Releasing terrorists in order for there to be negotiations and a meeting in Washington in a week's time -- we're getting nothing in return," Deputy Defense Minister Danny Danon complained on Israel Radio. "They're not in prison for traffic violations. They're major terrorists who have murdered, some with their own hands. They've kidnapped soldiers, buried them alive, shocking stories."
In his first public comment since Mr. Kerry's announcement, Mr. Netanyahu said in a statement that his goals in re-entering talks were "preventing the creation of a binational state between the Jordan River and the Mediterranean Sea," and "preventing the establishment of an additional Iranian-sponsored terrorist state on Israel's borders."
Saeb Erekat, the chief Palestinian negotiator, said he had "committed to John Kerry and President Abbas to shut up for 48 hours until we finalize everything, but things are looking good."
"It's really very, very hard, but I gave my commitment," said Mr. Erekat, normally the most talkative of Palestinian politicians. "We're going to do everything to make it work."
He said the Palestine Liberation Organization's executive committee, which had balked at the terms proposed in stormy sessions on Thursday, would meet again on Sunday, though it was unclear whether any action was required on its part for the deal to move forward.
The last round of direct talks between Mr. Netanyahu and Mr. Abbas, in 2010, fell apart after 16 hours of negotiations over three weeks, and the American-brokered deal this time includes a commitment for the process to last at least six months.
Still, several Israeli analysts said Saturday they were doubtful about its prospects.
"It's like marriage by a very brutal matchmaker," said Nahum Barnea, a senior columnist for the leading Israeli daily Yediot Aharonot. "The bride and the groom know each other very well, but they don't like each other." He said of Mr. Kerry's achievement, "It's not an agreement -- it's an agreement to have lengthy negotiations," and noted that negotiations "have been part of our life for a very long time."
David Horovitz, a 30-year journalistic observer of the peace process who now runs the news Web site Times of Israel, said that given Mr. Netanyahu's conservative government and Mr. Abbas's political weakness, he did not see how the new negotiations would succeed where previous rounds had not. In particular, he said, he could not imagine Mr. Netanyahu offering "anything close to" what his predecessor, Ehud Olmert, proposed in 2009, "and Abbas didn't take that."
"To me, the big issue was not whether Kerry would drag them back to the table," Mr. Horovitz said. "The question is how can they reach an agreement. I just don't see viable parameters that both sides could agree upon, to my great sorrow."
Michael R. Gordon contributed reporting from Washington.
This article originally appeared in The New York Times.