A senior White House official says U.S. President Barack Obama has authorized surveillance flights over Syria.
The official said late Monday that Mr. Obama has not approved any military action, but that the U.S. is preparing military options for combating the Islamic State fighters who have taken over large areas in eastern Syria and northern and western Iraq.
U.S. planes have been carrying out airstrikes in Iraq, helping Iraqi and Kurdish forces take back territory from the militants, including a dam in Mosul that is key to providing power to many in Iraq.
Pentagon officials have expressed the need to go after the Islamic State group on both sides of the border.
The operation is complicated by the ongoing civil war in Syria. White House officials say Mr. Obama does not want U.S. action to be seen as aiding Syrian President Bashar al-Assad, who has repeatedly blamed "terrorists" for the conflict that has raged in his country for more than three years.