Iraq has completely retaken Ramadi from the Islamic State group, but now faces the enormous challenges of removing bombs, reestablishing basic services and rebuilding the shattered city, officials said Tuesday.

Government forces recaptured areas on the eastern outskirts of the Anbar provincial capital from IS after weeks of fighting, and authorities say that all areas immediately surrounding the city have been retaken.

"All of Ramadi is now liberated" and responsibility for security is being handed over to local police, Anbar Governor Sohaib al-Rawi told journalists in Baghdad.

But the city's civilian population has been displaced, and "the biggest challenge before us is clearing the areas of mines" so residents can return, Rawi said, adding that he hopes to obtain international support to remove explosives.

Lise Grande, the UN's humanitarian coordinator for Iraq, said that clearing the city of explosives would cost an estimated $15 million.

"The key right now is to extract the IEDs (improvised explosive devices). This is the single largest, most difficult obstacle preventing people from coming home and rebuilding their lives," said Grande, speaking at a roundtable alongside Rawi.

But the city's problems go far beyond bombs.

- Widespread destruction -

"The level of destruction in Ramadi is as bad as anything we have seen anywhere in Iraq," Grande said.

"Houses are destroyed, bridges are destroyed, roads are infested with IEDs, water systems are ruined, schools are ruined, health centres are ruined and businesses are shut," she said.

Initial work will be in the Tamim area of southwestern Ramadi, and will include repairing the water system and six health centres, as well as providing six ambulances and dozens of generators, Grande said.

The second phase will focus on central Ramadi, and will include repairing water stations, bringing in three mobile electrical grids and connecting them to hundreds of generators, she said.

The UN has already secured the $10 million needed for the first phase, but the second will cost an additional $25 and $30 million, plus the cost of clearing explosives.

And even that is only the beginning: "Thousands of homes have to be rebuilt. Thousands of buildings have to be rebuilt," Grande said.

Rawi said that the provincial government had not received funds from Baghdad since the beginning of December, and that it will have to use part of its 2016 budget to pay debts from the previous year.

Iraq announced in December that it had recaptured Ramadi, located west of Baghdad, but daily fighting with IS jihadists continued for more than a month on the city's eastern outskirts.

- 'Famine' in Fallujah -

Iraqi forces "were able to liberate areas east of Ramadi" including Sichariya, Juwaiba and Husaiba, meaning that all areas immediately surrounding the city have been recaptured, the joint operations command said in a statement on Tuesday.

They "were also able to open the Ramadi-Baghdad road passing through Khaldiyah," it said, referring to a government-held area along the route.

IS overran large areas of Iraq in June 2014, but security forces and allied tribesmen held out in parts of Ramadi until May 2015, when the jihadists seized the city in an assault spearheaded by a wave of car and truck bombs.

But the capture of Ramadi was the last major advance by jihadists in Iraq, and Baghdad's forces slowly tightened the noose around it in the following months before moving into the city itself.

IS still holds Fallujah, east of Ramadi, and Mosul, Iraq's second city that is located in the north.

Fallujah has been largely cut off by security forces, and the situation inside the city "has reached a state of famine", Rawi said.

Iraq is deploying thousands of soldiers to an area southeast of Mosul for operations aimed at cutting supply lines linking it with areas farther south, which will set the stage for direct efforts to retake the city.