The Obama administration announced Sunday that indirect, American-brokered talks had resumed between Israel and the Palestinians, capping a year of efforts by Washington to revive the peace process.

The American special envoy to the region, George J. Mitchell, is expected to shuttle between the two sides over the next four months as mediator of the so-called proximity talks. They are aimed at forging a joint vision of the outlines of a solution based on the creation of a Palestinian state alongside Israel.

The State Department spokesman, Philip J. Crowley, released a statement warning both sides that “if either takes significant actions during the proximity talks that we judge would seriously undermine trust, we will respond to hold them accountable and ensure that negotiations continue.”

But he praised recent steps by both Israel and the Palestinians to help ensure that the talks could take place. Those included a statement from the Palestinian president, Mahmoud Abbas, that he would work to keep factions from trying to scuttle the talks through attacks or incitement, and from Prime Minister Benjamin Netanyahu of Israel that there would be no more construction at the Ramat Shlomo settlement in East Jerusalem for two years.

“They are both trying to move forward in difficult circumstances, and we commend them for that,” Mr. Crowley said.

Mr. Mitchell left the Middle East on Sunday after completing what the State Department characterized as the first round of talks, and was to return next week.

Expectations of an early breakthrough are low. Mr. Netanyahu, a conservative, has repeatedly stated his preference for direct talks, and had been hoping to limit the proximity talks to procedural matters. The Palestinians want the indirect talks to deal with the substantive issues of the Israeli-Palestinian conflict and have refused to engage in direct talks unless Israel declares a halt to all settlement construction in the West Bank and East Jerusalem.

Yasser Abed Rabbo, a Palestine Liberation Organization official and adviser to Mr. Abbas, said Saturday that the Palestinians had received assurances that all the core issues would be broached in the indirect talks, including the future of Jerusalem, the fate of the Palestinian refugees of 1948 and their descendants, borders, and security.

The talks were supposed to have started two months ago, but they were canceled after the Israeli government announced plans for 1,600 new housing units for Jews in contested East Jerusalem, causing a rift in Israeli-American relations.

Israel has since agreed to allow preliminary discussion of core issues in the indirect talks.

Ghassan Khatib, an analyst and spokesman for the Palestinian government in the West Bank, said last week that Israeli internal politics were “not conducive at all” for the prospects of an agreement. “But on the other hand,” he said, “we are encouraged by the international community, and especially the United States, whose efforts can have an effect on the Israeli position and on public opinion.”