The United Nations praised Palestinian Authority efforts at strengthening its institutions in a report on Tuesday, describing aspects of its administration as sufficient for an independent state.

The endorsement came at a crucial time for the Palestinian Authority, which has set a September deadline for the completion of its state-building program and is working toward international recognition of Palestinian statehood in the West Bank, Gaza and East Jerusalem that month.

September is also the target date set by Israel and the Palestinians to reach a negotiated agreement for a Palestinian state, but the latest round of peace talks has been stalled for six months.

A meeting of the so-called quartet of Middle East peacemakers — the United States, the European Union, the United Nations and Russia — that was scheduled for Friday in Berlin has been canceled amid disagreements over how to proceed.

The United Nations report, published on the eve of a Palestinian donor meeting in Brussels on Wednesday, echoed similar assessments by the International Monetary Fund and the World Bank in reports issued last week.

In the six areas in which the United Nations is most engaged — governance, rule of law and human rights; livelihoods; education and culture; health; social protection; and infrastructure and water — it said that the authority’s functions were “now sufficient for a functioning government of state.”

It warned, however, that the authority’s achievements were limited by the political and physical restrictions that the Israeli occupation has placed on further development. Some 60 percent of the West Bank’s territory remains under full Israeli control.

The report said that the Palestinian economy was helped by Israeli measures to facilitate movement and access, but that further steps were needed.

“I believe Israel needs to roll back measures of occupation to match the P.A.’s achievements,” Robert H. Serry, the United Nations special coordinator for the Middle East peace process, said in a statement. “I also stress the urgent need for Israeli-Palestinian peace negotiations on a two-state solution to resume, if the state-building and political tracks are to come together by September.”

The report noted an easing of restrictions on goods entering Gaza from Israel, but said an increase in construction materials was important to helping socioeconomic conditions in the coastal enclave, which is controlled by the authority’s rival, Hamas.

Israel strictly limits the importing of construction materials into Gaza to approved, internationally supervised projects, saying it fears that Hamas could use cement, iron and other materials for weaponry and fortifications.

Underlining the stark difference between the West Bank and Gaza — and the challenge that internal Palestinian divisions present to the goal of Palestinian statehood — the only commercial crossing between Israel and Gaza remained closed for a fourth working day on Tuesday, with Israel citing specific security threats against the terminal.

The Israeli Defense Ministry ordered the crossing at Kerem Shalom closed last Wednesday afternoon, a day before an antitank missile launched from Gaza hit an Israeli school bus, critically wounding a 16-year-old boy and setting off days of intense exchanges of fire that killed 18 Palestinians, about half civilians.

The Gaza-based Palestinian Center for Human Rights reported that 29 cooking-gas distribution stations had closed and that stores were running out of medicine.

Israeli security officials said that there were no indications of shortages and that more than 3,600 trucks carrying mainly food and medical supplies entered Gaza through the Kerem Shalom crossing in March. They added that an additional 1,100 trucks carrying paving and construction materials went through another crossing that was opened temporarily for that purpose despite the firing of rockets and mortar shells by Gaza militants at southern Israel last month.