The United States will not hesitate to strike the Islamic State of Iraq and the Levant terrorists in Syria, President Barack Obama said tonight, and the U.S. military is ready.

“Decisions about when to conduct these actions will be made at a prudent time as we continue to prosecute our comprehensive strategy against these ISIL terrorists,” said a senior defense official, speaking on background.

The president also announced he is sending more U.S. service members to Iraq as part of the strategy.

“Over the next week or so, approximately 475 additional service members will be deployed to Iraq to conduct the following missions: advise and assist the Iraqi security forces in order to help them go on the offense against ISIL, conduct intelligence, surveillance and reconnaissance flights to increase U.S. capacity to target ISIL, and coordinate the activities of the U.S. military across Iraq,” Pentagon Press Secretary Navy Rear Adm. John Kirby said in a statement.

Once these men and women arrive, 1,600 U.S. personnel will be in the country, Kirby added, not including service members serving in the Office of Security Cooperation-Iraq.

Of the 475 new troops, about 150 will supplement those already in Iraq conducting assessments of Iraqi security forces. These forces primarily operate from the joint Operation Centers in Baghdad and Irbil.

“The assessment mission they have been conducting will now transition to one of advise and assist,” Kirby said. “About a dozen teams will embed with Iraqi security forces at the Iraqi brigade level and above.”

Another 125 service members will support the operation of manned and armed intelligence, surveillance and reconnaissance platforms from Erbil, Iraq. “These forces include aircrews and maintenance personnel,” Kirby said. “Sending aircraft to Iraq will free up some of the unmanned assets we have been using to conduct additional operations in the region.”

Finally, about 200 personnel will provide headquarters command and control for the mission in Baghdad and Irbil. “These forces expand the headquarters of the Joint Forces Land Component Command, which has operational control over activities in Iraq and reports to the U.S. Central Command commander,” Kirby said.