BAGHDAD- An al-Qaeda splinter group vowed to seize the Iraqi capital today following its seizure of two provincial capitals earlier this week as the U.S. mulls action in the country it withdrew from almost three years ago.

"We have scores to settle," Abu Mohammed al-Adnani, a spokesman for the Islamic State of Iraq and the Levant, said in a recording posted on the group's website, referring to Iraq's Shiite-led government. "Do not give an inch of liberated land back and continue your march. The battle is not yet raging but it will in Baghdad."

In the video, whose authenticity could not be verified, al-Adnani promised the Sunni militants would also take the southern cities of Karbala and Najaf, both of which are holy for Shiite Muslims.

The militants who aim to create an Islamic state spanning Syria and Iraq captured Mosul and Tikrit earlier and already control the city of Fallujah and parts of Ramadi along with most of Anbar province.

The Iraqi parliament is expected to declare a state of emergency that would expand al-Maliki's powers to include declaring curfews.

U.S. officials have expressed concern over this development. State Department spokeswoman Jen Psaki said the U.S. likely will give Iraq new assistance to combat insurgents.

The U.S. is considering whether to conduct drone missions for Iraqi forces, the Associated Press reported, citing a senior Pentagon official who was not authorized to discuss the matter by name.

The U.S. already has expedited weapons sales to Iraq this year, including missiles, ammunition and other equipment. The advances in Mosul and Tikrit have rolled back gains made by American forces after the invasion in 2003.