The United Nations says it's temporarily pausing aid operations to neighborhoods in the eastern half of the Iraqi city of Mosul as attacks by the Islamic State group continue to inflict heavy civilian casualties there.

Lise Grande, the U.N. Humanitarian Coordinator for Iraq, says "the United Nations agencies made the decision that until security improves, it will be difficult for us to provide assistance."

She spoke during a visit to a camp for Iraqis displaced from Mosul on Wednesday.

While Mosul's eastern half was declared "fully liberated" last month, some neighborhoods continue to be hit by attacks claimed by IS.

The pause in aide comes as Iraqi forces are moving into positions ahead of an anticipated assault on Mosul's western half that is still firmly under IS control.