The United States is preparing to extend its reach in the effort to contain the group known as the Islamic State. Officials say Washington will do what it needs to do in order to protect American citizens.
Underscoring the possible internal threat in the United State from IS, a White House spokesman confirmed an NBC News that a California man was killed while fighting on the side of the militant group in Syria.
"We were aware of U.S. citizen Douglas McAuthur McCain’s presence in Syria and can confirm his death," said a statement released by Caitlin Hayden, a spokeswoman for the National Security Council.
"We continue to use every tool we possess to disrupt and dissuade individuals from traveling abroad for violent jihad and to track and engage those who return," she said.
U.S. authorities have said in recent months that dozens of Americans have joined forces with IS fighters.
On a day when the U.S. launched new airstrikes in Irbil, in northern Iraq, against the group known as the Islamic State, President Barack Obama sent a warning to its members.
"America does not forget; our reach is long. We are patient. Justice will be done," Obama said.
The remark was a reference to the Islamic State’s brutal execution of kidnapped U.S. journalist James Foley.
With the group continuing to make gains in neighboring Syria, Obama said the challenge is clear.
"Rooting out a cancer like ISIL won't be easy, and it won't be quick," said Obama.
The U.S. has been conducting as many as 60 surveillance flights a day over Iraq - with some peering across the border into Syria. Now, administration officials say President Obama has authorized similar flights over Syria itself.
Officials remain tight-lipped about whether that signals the U.S. is preparing to begin airstrikes against the Islamic State in Syria.
But Pentagon spokesman Rear Admiral John Kirby said whatever comes next, U.S. forces will be ready.
"We need to stay mindful of doing what we need to do to protect American citizens at home and abroad, and as has been stated before, we’re not going to hold ourselves to geographic boundaries to accomplish that job," Kirby said.
U.S. officials say the Islamic State is a regional threat with global aspirations. In addition to carrying out airstrikes in Iraq.
U.S. efforts have focused on strengthening Iraqi and Kurdish forces. And on Tuesday, several more countries agreed to help speed weapons and ammunition to Kurdish forces fighting on the front lines.
These efforts have not always satisfied Iraqi or Kurdish officials. The president of Iraq’s Kurdistan region credits Iran with being the first country to help supply needed arms.
Moderate groups in Syria, taking on both the regime of President Bashar al-Assad and the Islamic State, also have been waiting. A proposed U.S. program to get them more arms and training has yet to materialize.