A senior White House official says President Barack Obama has authorized surveillance flights over Syria.
The official said late Monday that 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 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.
White House Press Secretary Josh Earnest described the situation Monday as having "a lot of cross pressures."
"We're not interested in trying to help the Assad regime. In fact, we have been calling for a number of years now for the Assad regime to step down," said Earnest.
Earlier Monday, Syrian Foreign Minister Walid al-Moallem said Syria is open to working with the international community, including the United States and Britain, but that any attacks should be coordinated with the government in Damascus.
He warned that any unilateral U.S. action inside Syria "would be an act of aggression" that could result in Syrian air defenses attempting to shoot down American warplanes.