Official: US military takes extra precautions in Syria

FILE - In his photo April 4, 2017 file photo, provided by the Syrian anti-government activist group Edlib Media Center, which has been authenticated based on its contents and other AP reporting, shows victims of a suspected chemical attack, in the town of Khan Sheikhoun, northern Idlib province, Syria. A senior U.S. official says the U.S. has concluded that Russia knew in advance of Syria’s chemical weapons attack last week. (Edlib Media Center, via AP) (The Associated Press)

FILE - In his photo April 4, 2017 file photo, provided by the Syrian anti-government activist group Edlib Media Center, which has been authenticated based on its contents and other AP reporting, shows victims of a suspected chemical attack, in the town of Khan Sheikhoun, northern Idlib province, Syria. A senior U.S. official says the U.S. has concluded that Russia knew in advance of Syria’s chemical weapons attack last week. (Edlib Media Center, via AP) (The Associated Press)

FILE - In his photo April 4, 2017 file photo, provided by the Syrian anti-government activist group Edlib Media Center, which has been authenticated based on its contents and other AP reporting, shows victims of a suspected chemical attack, in the town of Khan Sheikhoun, northern Idlib province, Syria. A senior U.S. official says the U.S. has concluded that Russia knew in advance of Syria’s chemical weapons attack last week. (Edlib Media Center, via AP) (The Associated Press)

A U.S. military spokesman says the U.S. has taken extra defensive precautions in Syria in anticipation of possible retaliation against American forces for last week's cruise missile attack on a Syrian air base.

The spokesman, Col. John J. Thomas, told reporters at the Pentagon that the increased emphasis on defensive measures to protect U.S. troops on the ground in Syria led to a slight and temporary decline in offensive U.S. airstrikes against the Islamic State in Syria.

Thomas said there has been no Syrian retaliation for the cruise missile attack, which he said destroyed or rendered inoperable more than 20 Syria air force planes.

He said the U.S. intends to return to full offensive air operations as soon as possible.