( CNN ) -- The Syrian regime says it 's ready to accept support from the United States and others working under the U.N. umbrella to fight `` terrorists . '' The comments , by Syrian Foreign Minister Walid Moallem , were made Monday as ISIS fighters seized control of a strategically important air base in the country . The war-racked nation has been losing control of the northeastern region to ISIS militants . Moallem , however , warned against any unilateral action or strikes in Syrian territory without permission . `` Any effort to fight terrorism should be done in coordination with Syrian government , '' Moallem said . The U.S. military and intelligence communities are gathering intelligence on the locations of ISIS leadership and its troops in Syria , two U.S. officials told CNN on Friday . The information could be used in the coming days if President Barack Obama were to authorize airstrikes against the militants in Syria . Pentagon spokesman Rear Adm. John Kirby said on Monday , while speaking in general terms , that in order to conduct operations over Syria `` you certainly want to get as much of a view on the ground as you can . You want as much situational awareness as you can . '' `` Satellites can provide you good visibility , but you always want closer eyes on target if you can , '' Kirby added . Obama has authorized reconnaissance flights over Syria , which could begin at any point , a U.S. official told CNN on Monday . When asked by CNN 's Wolf Blitzer about how much coordination the United States would need to do with Syria to strike ISIS , Kirby said , `` Not getting into the hypothetical operations , there 's no intention to coordinate with Syrian authorities . '' Air base seizure . The Islamic extremist group , which has taken over large areas of Syria and Iraq , wrested the Al-Tabqa air base from the Syrian military on Sunday , according to the Syrian Observatory for Human Rights , a UK-based group that monitors the conflict . Syrian state television reported that the Syrian military had evacuated the air base in Raqqa province to regroup and was still carrying out strikes against ISIS fighters in the area . In Iraq , ISIS claimed responsibility on Sunday for three suicide car bombs that killed at least 20 people in the northern city of Kirkuk on Saturday . ISIS said in a statement posted Monday that the bombs were a response to secular Kurdish gangs that joined the war on ISIS and their involvement in the bombing and targeting of Sunni areas . The statement said that two of those who carried out the suicide attacks were German nationals , identified as Abu Yasser al-Almany and Abu Ibrahim al-Almany . When contacted by CNN , the German Foreign Ministry declined comment on the ISIS statement . ISIS , which refers to itself as the Islamic State , is part of the complex web of groups fighting in the long-running Syrian conflict -- a war that the U.N. estimates has killed more than 191,000 people . The spread of ISIS . Rebels have been battling the regime of Syrian President Bashar al-Assad since March 2011 , and the civil war has turned the country into a haven for jihadists . ISIS has thrived amid the chaos , gaining global notoriety for its brutal tactics , including the beheading of American journalist James Foley last week . After its break with al Qaeda this year , ISIS has grown in strength and reach . Its dramatic , murderous advance in northern and western Iraq this year provoked U.S. airstrikes aimed at helping Kurdish and Iraqi forces . U.S. and Kurdish officials say ISIS is now under pressure in Iraq . But the extremist group continues to win significant victories in Syria . Planes moved before base fell . Al-Tabqa air base is the last major military base in Raqqa province , which borders Turkey , to fall into ISIS ' hands . The group now is now understood to have effective control over the entire province , aside from a few villages in the south . The warplanes from the base had already been taken to other locations before ISIS took control , the Syrian Observatory for Human Rights reported . It said ISIS fighters were seen carrying the heads of Syrian regime soldiers . Both sides were reported to have suffered heavy losses in the battle for the base . ISIS controls major cities in Iraq and Syria , as well as oil fields , main roads and border crossings . It also has under its control more military hardware than some national armies after seizing both Iraqi and Syrian military bases and armories . Senior U.S. defense officials said last week that they had n't ruled out extending airstrikes against ISIS into Syria . CNN 's Hamdi Alkhshali contributed to this report .
NEW : Obama authorizes reconaissance flights over Syria , U.S. official says . Comment: But he warns against any unilateral action in Syrian territory without permission . Syrian state media reports that regime forces evacuated the base to regroup .