Army General Martin Dempsey, chairman of the Joint Chiefs of Staff, told a news conference at the Pentagon that Baiji was an important part of Iraq's oil infrastructure and also significant because it is on the road from Kirkuk to Mosul, which is occupied by Islamic State militants.
"It actually also sits on a corridor that runs from the Tigris River valley to the Euphrates River valley. And so it's geographically significant as well as significant economically," Dempsey said.
Control of the refinery has been hotly contested for months. Iraqi government forces recaptured it from the militants in November, lost control of it again and then recaptured it in April. Islamic State militants broke back into the perimeter earlier this week and have been slowly gaining ground.
A Pentagon spokesman said on Wednesday the fight was headed in the wrong direction and the outcome was impossible to predict. Iraqi troops at the refinery that day told Reuters they were low on food and ammunition, and pleaded for reinforcements."The Iraqis are under pressure there and have lost some control of the perimeter and some control of the road network that leads to it through the emplacement of ... IEDs (improved explosive devices)," Dempsey said.
"We've been working with them. We've conducted 26 airstrikes since the fifth of May," he said, adding that a U.S. mobile training team at Baghdad Airport had helped Iraqi forces rig air drops to resupply troops in the refinery.
A Pentagon spokesman said on Wednesday the refinery was not operational and its primary importance at the moment is that it sits astride a route to Mosul, the Iraqi city where an Islamic State leader last year proclaimed a caliphate to rule over all Muslims.
The spokesman indicated said it was unclear whether Mosul could be recaptured while Baiji remained in the militants' hands.
Get Breaking news, live coverage, and Latest News from India and around the world on NDTV.com. Catch all the Live TV action on NDTV 24x7 and NDTV India. Like us on Facebook or follow us on Twitter and Instagram for latest news and live news updates.