Secretary of State John Kerry said Sunday the United States would stick by Iraq in its battle with Al-Qaeda-linked militants, but stressed it was "their fight."
"We will stand with the government of Iraq who push back against (militant) efforts ... but it is their fight -- that is something we determined some time ago," he told reporters in Jerusalem.
Iraq lost Fallujah to Al-Qaeda-linked fighters, a senior security official said Saturday, putting militants back in control of the city west of Baghdad where US forces repeatedly battled insurgents.
And fighting in Anbar province killed 65 people -- eight soldiers, two government-allied tribesmen and 55 militants from the Al-Qaeda-linked Islamic State of Iraq and the Levant (ISIL), security officials said.
It is the worst violence to hit the province in years, and the first time militants have exercised such open control in major cities since the height of the bloody insurgency that followed the US-led invasion of 2003.
"We are very, very concerned" about ISIL, Kerry said.
"These are the most dangerous players in the region. Their barbarism is on display for all to see, their brutality is something have seen before.
"The United States will continue to be in close contact ... We will help them in their fight, but this is a fight in the end they will have to win and I'm confident they can."