A former chemical weapons facility in Iraq was seized by armed Islamist insurgents Friday as they continue to battle for control of the country's largest and most profitable oil refinery. 

The militants from the once al-Qaida-affiliated Islamic State of Iraq and Syria (ISIS) seized the former chemical weapons facility, which contains stockpiles of chemical weapons that are not considered usable. The former weapons complex was part of the arsenal of former dictator Saddam Hussein, according to The Washington Post

Jen Psaki, a spokeswoman for the U.S. State Department, confirmed that ISIS has occupied the chemical complex, which is located 36 miles northwest of Baghdad. 

"We remain concerned about the seizure of any military site [by the group]," she said in a statement. "We do not believe that the complex contains CW [chemical weapons] materials of military value, and it would be very difficult, if not impossible, to safely move the materials."

ISIS began fighting last week to gain control of Iraq, successfully seizing the city of Mosul. 

Grand Ayatollah Ali Sistani, the top Shiite cleric in Iraq, called on the country's parliament to start forming a new government now that the results of the April 30 parliamentary elections have been finalized. He criticized the government of Prime Minister Nouri al-Maliki, who has been blamed for the current crisis. Many believe he has excluded the Sunni minority during his administration, which is run by Shias. 

"It is necessary for the winning political blocs to start a dialogue that yields an effective government that enjoys broad national support, avoids past mistakes and opens new horizons toward a better future for all Iraqis," Sistani said in the sermon delivered by his aide, Ahmed al-Safi.

President Obama also criticized Maliki Thursday, urging Iraq's leaders to "rise above their differences" and govern with an "inclusive agenda." However, he did not tell Maliki to step down from his post. 

The weapons facility was bombed during the Persian Gulf War in 1991, which ended its run as a chemical weapons production facility. According to the CIA, U.N. weapons inspectors destroyed the stockpiles of weapons, and the remaining contents of the facility were looted. 

However, according to a 2007 CIA report, stockpiles of "chemical munitions" are still stored in the facility. While the most dangerous of the weapons are reportedly sealed in bunkers, the CIA reported that those areas of the compound "pose a hazard to civilians."

"Two wars, sanctions and [U.N. inspection] oversight reduced Iraqi's premier production facility to a stockpile of old damaged and contaminated chemical munitions (sealed in bunkers), a wasteland full of destroyed chemical munitions, razed structures and unusable war-ravaged facilities," the report said, according to The Washington Post

Meanwhile, fighting continued Friday between Iraqi military forces and Sunni militants for control of the country's biggest oil refinery in Baiji, which is located 140 miles northwest of Baghdad. 

Militants also seized control of an airport in Tal Afar earlier this week. 

Obama announced that the U.S. will send in up to 300 additional U.S. Special Operations troops in Iraq but made it clear that he would not have a substantial number of boots on the ground. He did not rule out U.S. air-strikes. 

Obama said that the troops will be "prepared to take targeted and precise military action if and when we determine that the situation on the ground requires it."

But, he said, "American combat troops are not going to be fighting in Iraq again. Ultimately, this is something that is going to have to be solved by Iraqis."

U.S. diplomats who are currently in Iraq are pushing for a new government to prevent a sectarian war from breaking out and to prevent more Sunnis from joining the militant forces. Diplomats have urged Maliki's rivals in the Iraqi government to rapidly form coalitions to establish a parliamentary majority. 

Vice President Joe Biden also called Osama al-Nujaifi on Wednesday, a Sunni speaker and a critic of Maliki. 

According to Nujaifi spokesman Dhafer al-Ani, Biden "didn't say he wanted Maliki out, but he said the United States didn't support Maliki. We made clear our position that we would not be part of a government headed by Maliki."

Obama said that in the meantime, his job is to "make sure American personnel there [are] safe, that we are consulting with the Iraqi security forces, that we're getting a better assessment of what's on the ground." 

Secretary of State John Kerry will travel to the region this weekend to meet with government leaders from the E.U. and the Middle East to discuss the Iraqi crisis.