"ISF have encountered heavy resistance from ISIL [Islamic State] forces using trenches and tunnels, IEDS [improvised explosive devices], suicide bombs, machine guns and small arms fires," Ryder tweeted.
ISF have encountered heavy resistance from #ISIL forces using trenches and tunnels, IEDS, suicide bombs, machine guns & small arms fires— U.S. Central Command (@CENTCOM) June 3, 2016
The spokesperson noted, however, that Fallujah has been further isolated and the Iraqi military is clearing the outskirts of the city.
In addition, the road networks in the Anbar province, where Fallujah is located, connect the territory held by the Islamic State terrorists.
"As ISIL [Islamic State] fights to keep Fallujah, we can expect them to look for opportunities to distract and delay Iraqi forces," Ryder added.
Fallujah is one of the last remaining strongholds for the Islamic State in Iraq, followed by Mosul, the country’s second largest city. It has become the first Iraqi city captured by the Islamic State in January 2014.
The Islamic State, also known as Daesh in Arabic, is outlawed in many countries around the world, including the United States and Russia.