Mogherini was among leaders and representatives from around 30 countries who gathered in the French capital to form an international response to the extremist group, which now controls a third of Iraq and parts of Syria.
While France has offered to join US air strikes in Iraq, Mogherini said Italy would not take part but will “send arms, munitions and, above all, material for humanitarian support, which is a priority,” according to a report on Ansa.
The international community is scrambling to contain the jihadists, who have beheaded aid workers and journalists in recent weeks.
US President Barack Obama has set out a strategy to defeat the group that would include air strikes in Syria and expanded operations in Iraq, where US aircraft have carried out more than 160 strikes since early August.
The US leader also foresees training "moderate" Syrian rebels to take on Isis and to reconstitute the Iraqi army, parts of which fled an Isis blitzkrieg across northern and western Iraq.