British foreign minister Philip Hammond said Iraqi forces are still months away from launching a full combat operation against the Islamic State [IS] group, which has seized large swathes of territory in the country's northern and western regions.

"It will be months yet before they are ready to start significant combat operations," Hammond told BBC Radio.

"This isn't going to be done in three months or six months. It's going to take a year, two years to push Isil (IS) back out of Iraq but we are doing the things that need to be done in order to turn the tide," he told Sky News.

His comments come on the day that member countries of the US-led coalition against IS meet in London for a one-day conference on how to tackle the threat of the group.

The ministers in attendance at the conference will include Iraqi Prime Minister Haider al-Abadi and US Secretary of State John Kerry.

Talks are set to focus on how the coalition can provide more military assistance to those fighting the group on the ground in Iraq and Syria, as well as humanitarian aid and thwarting the group's cashflow.

In addition to Britain, the US and Iraq, other countries taking part in the conference include: Australia, Bahrain, Belgium, Canada, Denmark, Egypt, France, Germany, Italy, Jordan, Kuwait, the Netherlands, Norway, Qatar, Saudi Arabia, Spain, Turkey, and the United Arab Emirates.