The first of the up to 300 military advisers President Barack Obama committed to help Iraq counter a Sunni militant surge have begun their assessment mission.
Pentagon spokesman Rear Admiral John Kirby told reporters two special operations teams started their work on Tuesday.
"We have begun to deploy initial assessment teams. Two special operations teams with approximately 40 personnel, previously assigned to the embassy through the Office of Security Cooperation, have started their new mission. In addition, approximately 90 additional troops assigned to help stand up the Baghdad joint operations center have arrived on station in Baghdad," Kirby said.
"Within the next few days, these troops will be joined by four additional teams of approximately 50 people total, who will deploy to Iraq from within the Central Command region," he added. "These teams will assess the cohesiveness and readiness of Iraqi security forces, hire headquarters in Baghdad, and examine the most effective and efficient way to introduce follow-on advisers."
Meanwhile, at the capitol in Washington, U.S. lawmakers are growing impatient. Following a briefing on Iraq. Republican Senator John McCain of Arizona said the U.S. needs to take action against Iraqi militants.:
"You can identify and take them out. And for us to have to quote 'assess the situation' as the continued flood of successes, success after success, that the ISIS are enjoying is a very very dangerous enterprise," McCain said.
The United States also is conducting air surveillance over Iraq, with 30 to 35 flights a day to help gain better insight about the security situation on the ground as Iraqi troops battle the fast-moving insurgency.
The advance of the Sunni militants -- al-Qaida breakaway group the Islamic State of Iraq and the Levant, or ISIL -- has sparked a crisis in Iraq.