BAGHDAD — Five years after bombings forced the United Nations to pull out of Iraq, the world body is back. It announced plans Wednesday to help Iraq rebuild and create jobs following complaints the government has been unable or unwilling to spend its oil riches.

An agreement signed by the U.N. and the Iraqi government outlined a series of steps to help the Iraqis improve spending. The U.N. will also aid in the funding of reconstruction, development and humanitarian projects.

With a budget of $2.2 billion through 2010, the U.N. hopes to use its know-how to train Iraqi bureaucrats and create incentives to develop the country's private sector. One of the main goals is to create jobs in a country where widespread unemployment especially in areas outside of Baghdad could undermine recent security gains if young men lose hope in their futures and turn to extremism.

The ambitious plans came ahead of the fifth anniversary of the Aug. 19, 2003, bombing at the U.N.'s Baghdad headquarters that killed 22 people, including top U.N. envoy Sergio Vieira de Mello.

The United Nations pulled out of Iraq in October 2003 after a second bombing at the organization's hotel headquarters and a spate of attacks on humanitarian workers.

It maintained a presence with Iraqi employees and allowed 35 international staffers to return in August 2004 but operations were sharply curtailed.

The current U.N. envoy to Iraq, Staffan di Mistura, said it was time to change that.

"There are moments when we wonder whether all this was worthwhile or not," he said at a memorial ceremony Wednesday. "I can tell you that what we are doing at the moment is sending a signal that the U.N. is back. The U.N. is back to stay."

As security has improved over the past year, the U.N. has steadily been raising its profile here. Di Mistura's deputy, David Shearer, said the organization currently has 140 international staffers around the country.

One of the biggest concerns is jobs.

"We have to be able to move a lot of the investment to the private sector," Shearer said at a joint press conference with Iraqi Planning and Development Minister Ali Baban. "Our biggest way of improving security is to make sure that young people are employed."

But Iraq's fledgling bureaucracy is ill-prepared to deal with that and other myriad problems facing the country, he said.

The ability of the Iraqis to solve their own problems and enable U.S.-led forces to go home has become a central issue in the U.S. presidential campaign.

"The Iraqi people are not ready to take over for themselves," John Nagl, an analyst with the private Center for a New American Security, said in Washington. "Iraqis do not yet know how to run a government and it is going to take some time to make this government function."

Last year, the Iraqi government spent only 34 percent of its $2.8 billion capital budget, and the ministries were unable to use more than 63 percent of their development funds, the U.N. estimated.

The estimated budget for the U.N. efforts through 2010 was estimated at $2.2 billion, with $322 million immediately available. The funding was provided by donor nations, U.N. contributions and the Iraqi government itself.

It's part of the International Compact with Iraq, a sweeping five-year economic and political reform package that the U.N. secretary-general helped broker in 2007.

"This represents an important step in Iraq's recovery process," Baban said. "It brings the whole U.N. organization together in partnership with Iraq and its people to reduce poverty, foster growth and consolidate democracy in our country."

Officials said security gains that have driven violence down to its lowest level in more than four years have paved the way for U.N. workers to gain better access to many areas. But they also stressed the need to maintain caution because the gains are fragile.

Underscoring that dangers remain, a series of car bombs ripped through northern Iraq on Wednesday, killing at least five people, officials said.

A roadside bomb also killed a U.S. soldier and an Iraqi interpreter in northwestern Baghdad, the American military said.

Brig. Gen. David Perkins, a U.S. spokesman, said insurgents "are feeling more and more pressure in their areas" because of military operations and want to show "they are still relevant."

But the attacks have failed to re-ignite retaliatory sectarian violence that had been common in recent years, he said, noting that no attacks were recorded in Baghdad the day after a triple suicide bombing that killed nearly 60 Shiite pilgrims last month.