JERUSALEM — Israel today approved the release of 441 Palestinian Arab prisoners and pledged not to build any new settlements in the West Bank, but it stopped short of American demands to halt construction in existing settlements before a crucial American-hosted Middle East conference.

Israel announced the moves ahead of a meeting between Prime Minister Olmert and the president of the Palestinian Authority, Mahmoud Abbas. The two men were trying to break a deadlock in preparations for the summit, expected to take place next week in Annapolis, Md.

Israel sees the conference primarily as a ceremonial launching pad for new peace efforts, while the Palestinian Arabs want a more detailed plan for how post-conference talks will proceed.

Mr. Olmert’s spokeswoman, Miri Eisin, said progress was made during the 21⁄2 hour meeting. She did not elaborate, but said negotiators would meet later to continue their work.

Seeking to drum up support for the conference, Mr. Olmert is heading to Egypt tomorrow for talks with President Mubarak, his office said. Arab League members are to decide on Friday whether they will join the gathering. High-level Arab attendance is seen as crucial to its success.

With the outcome of Annapolis uncertain, Israel has been under American pressure to take steps to bolster Mr. Abbas, including a settlement freeze and a large-scale release of Palestinian Arab prisoners.

A settlement freeze, and a related promise today to dismantle tiny settlement outposts, are key Israeli commitments under the “road map,” an American-backed peace plan that stalled shortly after its inception in 2003. The Palestinian Arabs, for their part, were supposed to crack down on militants.

America has been trying to revive the road map ahead of the peace conference.

At a Cabinet meeting, Mr. Olmert said Israel would not build any more settlements in the West Bank.

“Let’s be straight, we committed ourselves in the road map not to build new settlements and we will not build any,” Mr. Olmert was quoted as saying by Ms. Eisin.

But he indicated there would be no end to construction in existing settlements, as required by the road map.

“We won’t choke off under any circumstances the existing settlements,” Mr. Olmert said, according to another meeting participant, who spoke on condition of anonymity under Israeli civil service guidelines.

Israel has built no new authorized settlements in nearly a decade. But it has continued to rapidly expand existing settlements to accommodate what it calls “natural growth.”

Some 270,000 Israelis live in dozens of West Bank settlements, in addition to about 180,000 Israelis living in east Jerusalem. The Palestinian Arabs claim both areas for their future state.

In Washington, the State Department welcomed the Israeli moves.

“These would be important steps in advance of the Annapolis conference, important confidence-building measure steps,” a spokesman, Sean McCormack, told reporters.

But the Palestinian Arabs reacted coolly to Mr. Olmert’s announcement.

“Either it’s a 100% settlement freeze or no settlement freeze. There is nothing in the middle,” a Palestinian Arab negotiator, Saeb Erekat, said.

The Cabinet overwhelmingly approved Mr. Olmert’s proposal to release 441 prisoners. Although the release would be the largest in years, it fell short of Palestinian Arab calls to free some 2,000 prisoners. Israel holds an estimated 9,000 Palestinian Arab prisoners.

“We welcome the release of any prisoners,” the Palestinian Arab foreign minister, Riad Malki, said. “But this is not enough. We will continue demanding the release of all prisoners.”

Messrs. Olmert and Abbas have been meeting frequently to lay the groundwork for the American conference.

“We need to hear from him (Olmert) things that will satisfy us, so we can go to Annapolis on a solid basis,” Mr. Abbas told reporters shortly before his meeting with Mr. Olmert in Jerusalem.

The two men smiled and warmly embraced each other at the beginning of their meeting at Mr. Olmert’s official residence. Negotiators also smiled and made small talk, and Mr. Abbas paused to sign the residence’s guest book.

Ms. Eisin, the Israeli spokeswoman, said talks focused on carrying out the road map, as well as efforts to form a joint blueprint for peace, which they hope to present to the conference next week.

“There was progress,” she said, adding that negotiating teams planned to continue work later tomorrow. However, Israeli officials said significant gaps remained and there was a possibility there won’t be a joint statement at Annapolis.

The Palestinian Arabs want the document to address issues at the heart of the conflict with Israel, such as the borders of a future Palestinian Arab state, shared sovereignty over disputed Jerusalem, and the fate of Palestinian Arab refugees.

Israel says the summit should be a forum to formally renew peace talks, which broke down in violence seven years ago, with discussions on core issues to follow.