At a news conference in Germany, President Barack Obama has revealed the US does not yet have a “complete strategy” for helping Iraq regain territory from Islamic State (ISIS).
He said the Pentagon was reviewing ways to help Iraq train and equip its forces.
However, Barack Obama said a full commitment to the process was needed by the Iraqis themselves.
The president had earlier met Iraqi PM Haider al-Abadi on the sidelines of the G7 summit in Germany.
ISIS has recently made gains in Iraq despite US-led coalition air strikes.
In May the militants seized Ramadi, the capital of Anbar, Iraq’s largest province, as well as the Syrian town of Tadmur and the neighboring ancient ruins of Palmyra.
US officials cited a lack of training as a major factor in the fall of Ramadi.
However, Barack Obama said that the 3,000 US service personnel in Iraq sometimes found themselves with “more training capacity than we’ve got recruits”.
“We don’t have, yet, a complete strategy, because it requires commitments on the part of Iraqis as well about how recruitment takes place, how that training takes place,” Barack Obama told a news conference.
“We want to get more Iraqi security forces trained, fresh, well-equipped and focused and [Haider al-] Abadi wants the same thing so we’re reviewing a range of plans for how we might do that.”
President Barack Obama said he was “absolutely confident” ISIS would be driven out of Iraq if Haider al-Abadi has the support of the international coalition as well as a government that represents all the Iraqi people.
The president said all countries in the coalition were ready to do more to help train Iraqi security forces.
Iraq has become increasingly reliant on Iranian-backed Shia militias to take on ISIS in recent months.
The second day of the G7 summit in Germany is being dominated by the climate change and extremism talks.
German Chancellor Angela Merkel wants the economic powers group to reach an agreement on limiting global temperature rises.
Angela Merkel also wants G7 members to contribute to a fund for poor countries suffering the worst effects of climate change.
There will also be talks on the threat from radical extremism with the leaders of Nigeria, Tunisia and Iraq.
G7 summit is being held at the picturesque Schloss Elmau hotel in Krun in the Bavarian Alps.
It is being attended by President Barack Obama, UK PM David Cameron, Japanese PM Shinzo Abe, French President Francois Hollande, Canadanian PM Stephen Harper and Italian PM Matteo Renzi.
The first working session on June 8 will focus on climate and energy, with Chancellor Angela Merkel trying to get leaders to agree to keeping temperature rises within 2C of pre-industrial levels.
Angela Merkel is hoping to secure commitments from her G7 guests on tackling global warming to build momentum before a major UN climate summit in Paris in December.
Later, G7 leaders will be joined by Iraqi PM Haider al-Abadi, Nigerian President Muhammadu Buhari and Tunisian President Beji Caid Essebsi to discuss the threat posed by groups like Islamic State (ISIS) and Boko Haram.
On June 7, David Cameron said the UK was sending an extra 125 military trainers to Iraq to help in the battle against IS, describing the militants as “the biggest threat” G7 leaders had to address.
ISIS continues to control large swathes of Iraq and Syria despite being the target of a US-led air campaign against them.
In Nigeria, a similar regional battle is being fought against Boko Haram militants who have carried out attacks since 2009 to try to create an Islamic state.
The 41st G7 summit is held in Schloss Elmau, Krün, Bavaria, Germany on June 7–8, 2015.