Israel’s defense minister, Ehud Barak, authorized plans for 455 new housing units in Jewish settlements in the West Bank on Monday, in a move aimed at placating Israel’s pro-settlement camp before an expected construction freeze demanded by the Arab world and the United States.

But the details released by Mr. Barak’s office on Monday seemed to satisfy nobody, enraging not only the Palestinians, but also Israelis on the right and the left. The White House denounced the planned approvals last week, when news first emerged of Israel’s intention to grant them.

Still, in the strange and arduous choreography of Middle East peacemaking, Monday’s announcement was not seen as likely to derail movements toward renewing stalled Israeli-Palestinian talks.

Most, though not all, of the new housing units are to go up in settlement blocks close to the 1967 lines, areas that Israel intends to keep under any agreement for a Palestinian state. These are the first units to have been given final approval since the conservative-leaning government of Prime Minister Benjamin Netanyahu took office in late March.

Saeb Erekat, the chief Palestinian negotiator, said in a statement that Mr. Barak’s announcement posed a “serious challenge” to the American and international efforts to restart peace talks, but he stopped short of declaring a total settlement freeze a precondition for talks. Instead, he said the announcement about new building “nullifies” the effect any settlement freeze may have, and “further undermines faith in the peace process, and the belief that Israel is a credible partner for peace.”

The Palestinian president, Mahmoud Abbas, is under pressure from his party, Fatah. At a recent conference in the West Bank, the party’s first in 20 years, Fatah leaders approved a political program that called for no negotiations while Israel’s settlement building continued.

About 2,500 housing units are already under construction in the West Bank settlements. Israeli officials say they will be completed, regardless of any moratorium. They also say a moratorium will not apply to Jerusalem. The Palestinians claim the eastern part of the city as the capital of a future state.

It is not clear when construction of the additional 455 units will start, but settler representatives said it was their understanding that these units would not be subject to a freeze.

The seemingly paradoxical moves — a raft of approvals and then a formal freeze — represent Mr. Netanyahu’s attempt to balance competing political and diplomatic pressures. His own Likud Party supports settlement building, but the Israeli left and much of the international community denounce it.

Dani Dayan, chairman of the Yesha Council, the settlers’ umbrella organization, called the moves an “awkward compromise,” criticizing the freeze to come and playing down the significance of the “meager” 455 units Mr. Barak had approved.

On the left, Peace Now, an Israeli group that opposes all Jewish building in the occupied territories, criticized the approvals. “When we are on the eve of the possibility of moving forward, this is really like a provocation,” said Hagit Ofran, who monitors settlement-building for the group. “It serves as vindication for those who say there is no chance for peace.”

Amr Moussa, the secretary general of the 22-member Arab League, said he believed that there would be no negotiations unless Israel fully froze all settlement construction, including construction in Jerusalem. In an interview at the annual Ambrosetti forum, an international conference over the weekend in Italy, he said a freeze that included Jerusalem “would really change the atmosphere and allow the peace talks to begin.”

Most of the new units are to be built in the settlements of Har Gilo, Givat Zeev, Maale Adumim, Kedar and Alon Shvut, close to Jerusalem. More than 80 apartments will be built in Modiin Illit, an ultra-Orthodox settlement that is also close to the 1967 line. Twenty homes will be built in Maskiot, a barely populated settlement in the Jordan Valley.

The Americans have been trying to persuade Arab nations to offer Israel gestures in exchange for a building freeze, including reopening Israeli trade offices in several countries and allowing Israeli planes heading to Asia to use their airspace.

The Obama administration’s envoy to the region, George J. Mitchell, is expected in Jerusalem this weekend to continue negotiations toward a possible deal.