TEL AVIV — Vice President Joseph R. Biden Jr. came to Israel early this week to promote new Israeli-Palestinian peace talks and tighten the bonds between Israel and the United States. He left Thursday amid increased uncertainty over the nature and timing of those talks and with a sense of unease hanging over the American-Israeli relationship.

The cause of both was the unexpected announcement during his visit that Israel would build 1,600 housing units for Jews in East Jerusalem, where Palestinians hope to build the capital of their future state. That produced angry condemnation from Mr. Biden as well as signals of distress from the Palestinian leadership, which asked for American help to stop the project.

Both the housing construction and the talks are likely to go ahead. The chief Palestinian negotiator, Saeb Erekat, said by telephone on Thursday that the Palestinian president, Mahmoud Abbas, had asked Mr. Biden for help in stopping the housing project but that he had made no threat about pulling out of the talks. And Prime Minister Benjamin Netanyahu of Israel issued a statement regretting the timing of the housing announcement, though not its substance.

Still, the talks — indirect, so-called proximity talks — the first in more than a year between the sides, appear headed for trouble for another reason: differing expectations. The Palestinians want the talks to focus on borders and security; the Israelis want them to serve as a procedural corridor leading to direct negotiations.

Mr. Biden, who spent one day with the Israeli leadership and the next with the Palestinian leadership, gave a public address at Tel Aviv University on Thursday and spent most it expressing his personal devotion to Israel as well as the Obama administration’s “ironclad commitment to Israeli security.”

But the housing crisis caused him to add to his original text, explaining his condemnation.

“Sometimes only a friend can deliver the hardest truths,” Mr. Biden said. One truth, he said, is that “the status quo is not sustainable,” meaning that both Israel and the Palestinians needed to give up on certain claims and practices in order for the two to live in neighboring states.

He indicated that for Israel, that meant giving up territorial claims, and recognizing that the Palestinian president, Mr. Abbas, and Prime Minister Salam Fayyad represented the first Palestinian leadership with which Israel could make long-term peace. For the Palestinians, it meant ending anti-Israel incitement.

As Mr. Biden left, however, the Israeli-Palestinian gap on a range of issues seemed as wide as ever.

Mr. Netanyahu issued a kind of apology over the timing of the housing announcement, saying it would probably be several years before any of the units, planned for the ultra-Orthodox neighborhood of Ramat Shlomo, would be started. But he and his lieutenants offered no regrets about building inside the boundaries of Jerusalem as defined by Israel.

Israel’s centrist Kadima Party and the left-of-center Labor Party believe that Jerusalem must somehow be shared with the Palestinians, although neither has laid out exactly how. Mr. Netanyahu, the Likud prime minister, has acknowledged that Jerusalem will be a topic of negotiation but has said he believes that it must remain entirely under Israeli sovereignty.

Much of Mr. Biden’s discussions with Israeli leaders entailed an American effort to end the Iranian nuclear program through international sanctions rather than any Israeli military attack. He said at his Tel Aviv address on Thursday, to robust applause, “The United States is determined to prevent Iran from acquiring nuclear weapons.”

His next stop was Jordan, for a meeting with King Abdullah II.

2 Charged in Gaza Episode

JERUSALEM — The Israeli military prosecutor charged two staff sergeants on Thursday with instructing a 9-year-old Palestinian boy to open bags the soldiers suspected were booby-trapped, during Israel’s military campaign in Gaza just over a year ago.

The military said in a statement that “soldiers were strictly forbidden from making use of civilians for or during operational activity and specifically when it endangered the lives of the civilians.” If convicted, the soldiers, who are now in the reserves and were not named, could face up to three years in jail.