ERBIL, Iraq (Thomson Reuters Foundation) - The U.N. World Food Programme (WFP) is working on contingency plans that up to 700,000 people could be displaced by a planned offensive to retake Iraq’s second largest city from Islamic State, according to its head in Iraq.

United Nations World Food Programme country director in Iraq Jane Pearce speaks during an interview at the United Nations office in Erbil, Iraq, on May 20, 2016. REUTERS/Sebastien Malo

Iraqi forces, with help from a U.S.-led coalition, are expected to push later this year to retake Mosul, Islamic State’s de facto capital in Iraq.

WFP’s country director in Iraq, Jane Pearce, said she feared the violence ahead but remained confident the agency was as well-prepared as possible for the event.

“I’m fearful for what the people may suffer and for what destruction may be leveled against a really beautiful city that has been a center of culture and learning for centuries,” Pearce told the Thomson Reuters Foundation.

“I feel confident that the organization will do its best to make sure that the people get the assistance that they need,” she said in an interview in Erbil, capital of Iraq’s autonomous Kurdish region, where many aid operations are coordinated.

WFP helps some 1.5 million people across Iraq with food, vouchers or money - most of them the casualties of conflict inside Iraq and war in neighboring Syria.

Last Friday, the United Nations refugee agency UNHCR said more than 4,200 Iraqis from Mosul had fled to Syria in May, adding that it was gearing up for up to 50,000 people to leave the city and cross the border.

Pearce said uncertainties over the shape of a military assault on Mosul represented a challenge in planning a humanitarian response.

“Are they going to siege the town, like they’re doing in Falluja, which means that when we do get access to (civilians) we don’t know what state they’re going to be in,” Pearce said.

“Or is it going to be an overthrow and then they all come out?”

Citing witness accounts, UNHCR said on Monday that Islamic State forces are reported to be holding several hundred families as “human shields” in Falluja while government forces close in.

Falluja has been under siege for more than six months. Foreign aid groups, who are not present in the city, are providing help to those who manage to escape to refugee camps.

Pearce said WFP had been preparing for the expected Mosul offensive by stocking up on food with the help of U.S. funding.

Though the agency is preparing for 700,000 displaced people, its contingency plan has been designed to assist as many as 900,000 people, the agency said.

“I’m trying to get to the point where I have a month’s food in country at all times so that if there is a big outflow I have something in country already,” she said. “I’m almost there.”

After a career that has brought her to live in Iraq for some 10 years on and off, Pearce said her appreciation for the country had only grown.

But asked how she saw the immediate future unfolding, Pearce said: “There’s going to be a lot more violence ... that we’re going to have to deal with.”