In a 17-minute long video posted online Thursday morning, ISIS spokesman Abu Mohammed al-Adnani urged ISIS fighters to "Continue your march as the battle is not yet raging."
The ISIS official warned of more attacks to come. The "battle," al-Adnani said, "will rage in Baghdad and Karbala. So be ready for it."
The U.S. Department of State said Wednesday that it is closely monitoring "the deteriorating security situation" throughout the country.
"You can expect that we will provide additional assistance to the Iraqi Government to combat the threat from ISIL," State Department spokesman Jen Psaki said, adding "but I'm not in a position to outline that further at this point."
Meanwhile, U.S. Embassy Baghdad issued a warning to U.S. citizens in Iraq, advising them to avoid Anbar, Ninewah, and Salahdin provinces where large-scale militant fighting continues. The State Department issued an updated travel warning on Wednesday to caution Americans against unnecessary travel to Iraq.