Image copyright AP Image caption Iraqi Security Forces and local fighters are attempting to retake Ramadi

The US is willing to do more to assist the Iraqi army in its fight to retake the city of Ramadi from the so-called Islamic State (IS), US Defence Secretary Ash Carter has said.

Mr Carter told a Senate panel that military advisers and helicopters could be deployed to help "finish the job".

However, their deployment is incumbent upon a request from Iraqi Prime Minister Haider al-Abadi.

IS captured the city in May after an embarrassing defeat for the Iraqi army.

Colonel Steve Warren, spokesman for the US campaign against IS, told the BBC that Mr al-Abadi has so far not asked for the helicopters.

As a fight to retake the city has brewed, the US-led coalition has provided training and equipment to the Iraqi army, including 5,000 AT4 shoulder-fired missiles to counter truck bombs.

This is in addition to the on-going air strike campaign known as Operation Inherent Resolve.

Image copyright AFP Image caption Sources tell the BBC that the US forces are providing advice from the al-Taqaddum airbase

Image copyright Getty Images Image caption Ramadi and surrounding area fell to IS in May after an embarrassing defeat for Iraqi security forces

In recent days, Iraqi forces have made progress towards recapturing the city - which is located about 90km (55 miles) to the west of Baghdad - including the retaking of a military operations centre and a suburban neighbourhood.

But Mr Carter warned of a tough fight ahead.

Critics of the Obama strategy to counter IS have said air power alone will not defeat them.

In October, the US said it would send dozens of special operations forces into Syria to assist anti-government rebels in fighting. Last week the US said it would send elite teams into Iraq to carry out raids, free hostages and capture IS leaders.

"They are not giants," Senator John McCain said at Wednesday's hearing. "Someone's going to have to convince me that air power alone and special operations forces are going to succeed in the short-term."

The defence secretary said a large-scale deployment of US troops would "Americanise" the conflict and create more militants.

The US military's recent estimates suggest there are between 600 and 1,000 IS militants in Ramadi.

Mr Carter was testifying in front of the Senate Armed Services Committee at a time when the US public is growing increasingly concerned about the threat of terrorism.

It is also the first time he spoke to the committee since the attacks in Paris, Beirut, against a Russian airliner in Egypt, as well as the deadly rampage in California by a radicalised Muslim couple.