The United States is considering deploying 100 special operations troops to advise the Iraqi army in its defence of Baghdad from Sunni extremists, a US defence official says.

The president is “leaning” toward a limited course of action that would “embed” the commandos – already at the ready in the region – with Iraqi forces but not call for US bombing raids, the official told AFP.

US President Barack Obama is set to make a statement on Iraq on Thursday as he faces rising pressure to respond to rampant advances by Sunni militant fighters.

Obama will appear in the White House briefing room at 1630 GMT and is likely to bolster US warnings that Iraqi Prime Minister Nuri al-Maliki must drop what Washington sees as a sectarian approach to governing, which has worsened the situation in the country.

Obama’s statement comes as he studies options for responding to the swift offensive of the Islamic State of Iraq and the Levant (ISIL) which has grabbed swathes of territory in Iraq and threatens to splinter the country along sectarian lines.

The White House says that the president has not taken any options off the table, apart from the dispatch of ground troops into a war he declared had ended at the end of 2011.

Possible courses of action by the United States include the use of manned or unmanned air strikes or more funding and training for the Iraqi military.

Obama could also decide to send special forces troops to Iraq, which could be used to train the Iraqi army or to call in eventual air strikes against militant targets.