UNITED NATIONS (CNN) -- The U.N. Security Council on Friday unanimously passed a resolution that expands the mandate of its mission in Iraq.
At least seven people died as a car bomb exploded in a busy marketplace in Kirkuk, Iraq.
Zalmay Khalilzad, U.S. ambassador to the United Nations, said this "marks an important new phase in the U.N.'s role in Iraq."
The resolution, which passed 15-0, says the United Nations Assistance Mission for Iraq seeks to "foster regional dialogue" on matters such as "border security, energy and refugees." It will work with the Iraqi government to "resolve disputed internal boundaries" and will promote discussion on national reconciliation. It also will help plan a census.
The mission has had a limited and relatively circumspect role in the country, where it greatly scaled down activities after two bombings in 2003 at its Baghdad headquarters.
The bombings and attacks against humanitarian workers spurred former U.N. Secretary-General Kofi Annan to remove all U.N. international staff from Iraq later that year.
The top U.N. envoy to Iraq, Sergio Vieira de Mello, and 21 others were killed in the first bombing. A year later, a small U.N. contingent returned to Baghdad.
Meanwhile Friday in Kirkuk, Iraq, at least seven people were killed -- including women and children -- and dozens more injured in a suicide car bomb explosion at a busy outdoor market, police said.
A police official said the attack took place in the Hurriya district, a Kurdish area in the northern Iraqi city 149 miles (240 kilometers) from Baghdad. Kirkuk has a mixed ethnicity, with large populations of Arabs, Kurds and Turkmens.
The blast wounded at least 47 people and damaged nearby shops, houses and cars.
South of Baghdad, two U.S. soldiers were injured as a military helicopter was forced to make a "precautionary landing" during a raid early Friday in Yusufiya, 10 miles (16 kilometers) from the capital, Iraqi and U.S. authorities said.
"Initial reports from ground forces do not clearly identify the cause of the mishap while in transit to the proposed target," the U.S. military said.
The incident was the second of its type in recent weeks. On July 31, the crew of a U.S. Apache helicopter was successfully evacuated when it was forced to land after coming under attack from ground fire.
Meanwhile, the U.S. military reported the deaths of five insurgents Friday and the detention of more than 30 others in operations targeting militants in central and northern Iraq.
Iran's supreme leader, Ayatollah Ali Khamenei, on Friday asserted "full support for the popular government of Iraq" as Iraqi Prime Minister Nuri al-Maliki continued an official visit to his country's predominantly Shiite neighbor.
But Khamenei reiterated his regime's assertion that the "presence of occupying forces" was Iraq's top problem and said Tehran was eager to see an "independent" Iraq, Iran's Islamic Republic News Agency said.
Khamenei, who hosted al-Maliki in the city of Mashhad on Thursday night, said national unity was "the key to solving problems" and urged Iraq's various ethnic and religious groups to cooperate.
He said the presence of occupying forces had been disastrous for Iraq and predicted that U.S. policy there was destined to fail, the Islamic Republic News Agency reported.
The United States has asserted that Shiite militants in Iraq are being armed and trained by Iranian agents, but Iran has denied that claim.
President Bush on Thursday said Iranians who smuggled bombs to insurgents in Iraq would face "consequences" if they continued.
Al-Maliki's office said the prime minister had told Khamenei that the government was "proceeding with the political process despite security problems."
"Al-Maliki said that the new Iraq after the fall of the dictatorship will be for all and there is no marginalization or excluding to any party," a statement said. E-mail to a friend
CNN's Richard Roth contributed to this report.