UNITED NATIONS (AP) — The U.N. secretary-general urged Iraqis to take advantage of the recent decrease in violence and deaths to work across ethnic, sectarian and political lines for national reconciliation.

September witnessed the lowest number of Iraqi casualties this year, an easing of violence that holds "significant political potential," Ban Ki-moon said in a report to the U.N. Security Council circulated Wednesday.

"There is now an opportunity that should not be missed," said Ban. "Against a backdrop of daily attacks, continued high levels of displacement and political gridlock, there have been some positive signs," he added. "The political challenge for the months ahead will be to transform these military-political developments into a basis for national reconciliation."

According to AP figures, 988 Iraqi civilians, police and military died in September, 50 percent fewer than the previous month and the lowest tally since June 2006, when 847 Iraqis died. The actual number is likely higher, as many killings go unreported. In the past, other sources have given different — and sometimes higher — death tolls than the AP.

Despite the decrease, Ban said, "widespread insecurity continues to make national dialogue challenging, and increasing levels of displacement add to an already alarming humanitarian crisis."

According to the new report, the estimated number of Iraqi refugees and internally displaced rose to 4.2 million, with more than 60,000 Iraqis fleeing their homes every month compared to 50,000 six months ago.

"Political compromise and genuine attempts to work across ethnic, sectarian, and political lines are needed now more than ever," Ban said. "The Iraqi people and the international community have high expectations for the government and they expect bold steps intended to provide a basis for peace and stability in the country."

The report is the first in response to a Security Council resolution adopted on Aug. 30 that expanded the U.N. role in Iraq to facilitate discussions among different Iraqi factions, ethnic and religious groups.

The resolution also authorizes the U.N., at the request of the Iraqi government, to promote a regional dialogue on issues including border security, energy and refugees as well as help tackle the country's worsening humanitarian crisis which has spilled into neighboring countries.

He said the U.N. was ready to help resolve internal boundaries issues, alluding to a number of disputes including rival claims to the oil-rich city of Kirkuk in northern Iraq. The U.N. is also prepared to assist in drafting laws that are critical to national reconciliation including on the division of Iraq's oil revenue.

Ban urged donors to replenish a trust fund to protect the U.N. in Iraq, which will be exhausted in November, and to provide logistical and technical support including aircraft. He also said the U.N. is looking at the possibility of re-establishing an office in the southern city of Basra.