Peace Now, the Israeli advocacy group, said in a report released Tuesday that in the last year Israel had nearly doubled its settlement construction in the occupied West Bank, in violation of its obligations under an American-backed peace plan.

Secretary of State Condoleezza Rice, in Jerusalem on a short visit to help Israeli and Palestinian leaders in their negotiations, said when asked about the report that she had told Israeli officials that such building did not advance the cause of peace.

“What we need now are steps that enhance confidence between the parties, and anything that undermines confidence between the parties ought to be avoided,” she said with the Israeli foreign minister, Tzipi Livni, at her side.

Ms. Livni said that settlement building should not influence the negotiations because the goal should be “not to let any kind of noises that relate to the situation on the ground these days enter the negotiation room.”

Earlier, Ms. Rice had made clear that neither Israelis nor Palestinians had fully lived up to their obligations. Israel is supposed to end all settlement building and remove illegal settlement outposts, while the Palestinians are supposed to dismantle terrorist infrastructures.

Negotiators had hoped for a full two-state peace framework between the Palestinian Authority and Israel to be completed by the end of President Bush’s term. Lately, though, they have cautioned that such an aim may be out of reach although the talks, they say, are making progress.

Most say they prefer to continue the process rather than try to put together a partial document. But Prime Minister Ehud Olmert, who has pledged to resign after his Kadima Party chooses a new leader in September, seems eager for an agreement before his term ends to burnish his legacy.

Standing with the Palestinian president, Mahmoud Abbas, in Ramallah after their meeting, Ms. Rice said that “God willing,” and with the hard work of the negotiators, the two-state goal could still be attained before year’s end.

Mr. Abbas seemed already to be looking beyond the Bush administration, however, and expressed hope that its successor “will continue what we have begun.”

He also complained about the increased settlement building.

The Peace Now report on settlements, based on aerial photos, visits and government data, says that more than 1,000 buildings are going up in the West Bank, including 2,600 housing units. It says that for the first five months of 2008, construction in the settlements was 1.8 times greater than in the same period of 2007.

Peace Now opposes Israeli construction on land captured in the 1967 war, like the West Bank, and favors furthering the creation of a Palestinian state there. Yet it is considered a reliable source of settlement information.

Its report says more than half of the building is beyond the separation barrier that Israel has built in recent years on the border of and inside the West Bank. This is significant, if true, because Israeli leaders have argued that ultimately a deal with the Palestinians will allow it to keep several settlement blocs and neighborhoods in East Jerusalem in exchange for land swaps. Therefore, they say, their building in East Jerusalem and close-in settlements on their side of the barrier should cause no concern.

The Peace Now report shows that the building in East Jerusalem is intensive, with the number of tenders for houses there up to 1,761 this year from 46 in 2007.

A spokesman for Israel’s Housing Ministry, Eran Sidis, said he could not check on all the data in the Peace Now report, but he defended building in areas Israel hopes to keep, saying, “There’s nothing to prevent strengthening settlement blocs that in the end of the day, in a peace agreement, will clearly be in Israel’s hands.”

American and Palestinian officials reject the idea that such building is harmless to negotiations. In addition, the Peace Now report challenges the government’s assertions that it is limiting construction to the western side of the barrier by showing that beyond the barrier, building continues apace. It also says that in the illegal outposts that were supposed to be removed, 125 new structures have been added, including 30 permanent houses.