The 300 special forces advisers were assigned by US President Barack Obama to help the Iraqi government deal with the ISIS offensive across the country, after making weapons contingent on the formation of an inclusive government in Baghdad. 

Iraq's Prime Minister Nouri Maliki WEdnesday rejected US calls to Iraq’s political leaders to form an emergency "national salvation" government. These calls, he said, represented a "coup against the constitution and an attempt to end the democratic experience.”

Government forces have been unable to recapture the territory seized by jihadist ISIS fighters this month. Fighting was reported to have continued on Wednesday, with an attack on the Balad airbase, about 80km north of Baghdad.

US Secretary of State John Kerry has arrived in Brussels to meet NATO leaders and report on his two-day efforts in Baghdad and Irbil to replace the Maliki government.