President Barack Obama has decided there will be a response to the Syrian government's alleged use of chemical weapons, and the White House says he is now working with his national security team to determine what it will be.
Spokesman Jay Carney says there was "no doubt" that poison gas was used during an August 21 attack in suburban Damascus.
At a Tuesday briefing, Carney said there is very little doubt the Syrian government was responsible for the attack, which he called a "flagrant violation" of international laws.
"The president believes that this is a grave transgression and it merits a response," he said. "He will obviously take the time necessary to evaluate the options available to him in deciding upon what is the appropriate response by the United States in consultation with our allies and partners in consultation with leaders in Congress."
Carney also said that later this week the U.S. will release an intelligence report on the poison gas attack.
The Syrian government has denied launching any chemical attack and has blamed rebels for last's week strike that left hundreds dead.
Earlier Tuesday, U.S. Defense Secretary Chuck Hagel said the American military is ready to act against Syria for its alleged use of chemical weapons. Hagel told the BBC that the U.S. military has "moved assets in place" and will be able to "fulfill and comply" with any option President Obama wishes to take.
News reports say the U.S. and several other Western powers are considering a limited, targeted response to Damascus' alleged use of chemical weapons to punish Syrian President Bashar al-Assad.
A U.N. team is in Syria to investigate the alleged use of chemical weapons but its mission was delayed Tuesday due to security concerns.
Stephen Zunes, a professor of Middle East studies at the University of San Francisco, says that while there is pressure on the United States to take military action, there are limits to what strikes can accomplish.
"The impulse is quite understandable, but on a practical level it does not seem that it would make such a difference in terms of the military balance, given that the rebel forces are divided into literally hundreds of different militia, some of which are as anti-Western or more so than the regime," he said.
Michael O'Hanlon, a Brookings Institution foreign policy and security expert, says Obama had been reluctant to step up U.S. engagement in Syria. However, he told Alhurra TV that Assad has pushed the U.S. and the international community "one step too far."
"What President Assad has done is to force President Obama to consider options that previously that he had not been willing to consider, and I think President Assad is going to realize that he made a very tragic mistake, not only for the hundreds of people killed but even for the good of his own regime."
The U.S. on Tuesday postponed a meeting with Russian officials scheduled for later this week to discuss the situation in Syria.
Russia and China have repeatedly blocked actions at the United Nations to impose sanctions on the Syrian government for assaults on the civilian population during the civil war.
Some information for this report was provided by AP, AFP and Reuters.
In this citizen journalism image provided by Edlib News Network, ENN, Syrians search under rubble to rescue people from houses that were destroyed by a Syrian government warplane in Idlib province, August 30, 2013.
In this citizen journalism image provided by Edlib News Network, ENN, smoke rises after explosives were dropped by a Syrian government warplane in Idlib province, August 30, 2013.
In this image taken from video obtained from the Shaam News Network, U.N. investigators gather potential evidence in a Damascus suburb, August 28, 2013.
This citizen journalism image provided by the United media office of Arbeen shows Syrians moving a man who was allegedly exposed to chemical weapons to show him to U.N. investigators in a Damascus suburb, August 28, 2013.
This citizen journalism image provided by the United media office of Arbeen shows U.N. investigators in a suburb of Damascus, August 28, 2013.
Free Syrian Army fighters carry their weapons as they escort U.N. vehicles carrying chemical weapons experts at the site of an alleged chemical weapons attack in a Damascus suburb, August 28, 2013.
Free Syrian Army fighters deploy in Aleppo's town of Khanasir after seizing it, August 26, 2013.
Free Syrian Army fighters inspect munitions and a tank that belonged to forces loyal to Syria's President Bashar al-Assad after they seized Khanasir, August 26, 2013.
A U.N. chemical weapons expert gathers evidence at site of an alleged poison gas attack in a southwestern Damascus suburb, August 26, 2013.
An image grab taken from a video posted by Syrian activists purportedly shows a U.N. inspector speaking to a man in a Damascus suburb, August 26, 2013.
U.N. chemical weapons experts visit a hospital where wounded people affected by a suspected gas attack are being treated, in a southwestern Damascus suburb, August 26, 2013.