Timeframe set for destroying IS: Julie Bishop

Foreign Minister Julie Bishop says after meeting with US officials that there is a timeframe by which they believe Islamic State will be destroyed.

Iraqi security forces work at the site of a mass grave contain the bodies of Iraqi civilians killed by IS group militants in Ramadi Source: AAP

The US-led coalition against Islamic State is working to a timeframe by which it believes the extremist organisation can be destroyed, with recent progress having prompted "a level of optimism", Foreign Minister Julie Bishop says.

The foreign minister, who has been holding high-level talks in Washington, including meeting on Thursday (AEDT) with US Vice-President Joe Biden, said progress was also being made in reaching a political solution to end the five-year-old civil war in Syria.

Ms Bishop also met CIA director John Brennan, US Director of National Intelligence James Clapper and Susan Rice, the National Security Adviser to President Barack Obama.

Speaking from Washington, Ms Bishop said the taking back of the Iraqi city of Ramadi from IS forces this month was seen as a "turning point" in the conflict.

She confirmed there is also a timeframe by which the US administration believes the IS group can be destroyed, although she refused to provide details.

"They do have timeframes but I won't share them," Ms Bishop told Sky News.

"But certainly we had a detailed discussion on strategy as well as tactics as to how we will defeat this organisation."

Iraqi forces, backed by coalition air support, were able to wrest back control of the western Iraqi city of Ramadi this month.

The victory comes amid reports from the US-led coalition that IS's territory shrank by 40 per cent in Iraq and 20 per cent in Syria last year.

The extremist group cut a swathe through a third of Iraq in 2014, taking the large city of Mosul and reaching the outskirts of the capital, Baghdad.

Ms Bishop said progress was also being made in terms of reaching a solution in Syria.

"There is progress being made and the relevant parties to the civil war in Syria are being pulled together for a meeting so that we can progress a solution that involves a political outcome in Syria."

The comments come, however, amid reports that plans to hold negotiations to end the civil war are in doubt after opposition negotiators said they would not attend unless attacks on civilian areas first stopped.