President Barack Obama will meet with his national security advisers early on Saturday at the White House to discuss reports that the Syrian government used chemical weapons this week in an attack on a Damascus suburb, a White House official said in a statement.
The United Nations disarmament chief arrived in the Syrian capital on Saturday to press President Bashar Assad's regime to allow UN experts to investigate the alleged chemical assault, whose reported death toll ranged from 136 to 1,300.
Obama has been reluctant to intervene in Syria's 2-1/2-year civil war, which he has described as a "sectarian complex problem." But a year ago he said chemical weapons would be a "red line" for the United States, and he is now under pressure to take action.
"We have a range of options available, and we are going to act very deliberately so that we're making decisions consistent with our national interest as well as our assessment of what can advance our objectives in Syria," the White House official said.
The U.S. Navy repositioned a ship armed with cruise missiles in the Mediterranean on Friday. Defense Secretary Chuck Hagel said Obama had asked the Pentagon for options on Syria.
American and European security sources said on Friday that U.S. and allied intelligence agencies had made a preliminary assessment that chemical weapons were used by Syrian forces in the attack near Damascus this week.
"As we have previously stated, the President has directed the intelligence community to gather facts and evidence so that we can determine what occurred in Syria. Once we ascertain the facts, the President will make an informed decision about how to respond," the White House official said.
United Nations High Representative for Disarmament Affairs Angela Kane arrived in Damascus on Saturday to push for access to the suspected chemical weapons attack site for UN inspectors, who are already in Syria to investigate months-old accusations.
So far Syrian President Bashar Assad's government has not said whether it will allow access to the site despite being under increasing pressure from the United Nations, Western and Gulf Arab countries and Russia. If confirmed, it would be the world's deadliest chemical attack in decades.
'Chemical agents in rebel tunnels'
Also on Saturday, Syrian state television said troops found chemical agents in rebel tunnels in a Damascus suburb on Saturday and some soldiers were "suffocating", intensifying a dispute over blame for a reported nerve gas attack that killed hundreds this week.
In a clear attempt to strengthen the government's denials of responsibility for the suspected chemical assault, Syrian state television said soldiers came across chemical agents in rebel tunnels in the suburb of Jobar and some were overcome by fumes.
"Army heroes are entering the tunnels of the terrorists and saw chemical agents," it quoted a "news source" as saying. "In some cases, soldiers are suffocating while entering Jobar. Ambulances came to rescue the people suffocating in Jobar."
An army unit was preparing to storm the insurgent-held suburb, the television added.
Syrian opposition activists accuse Assad's forces of firing nerve gas projectiles into Jobar and other rebellious suburbs before dawn on Wednesday. Later in the week, activists crossed front lines around Damascus to smuggle out tissue samples from victims of the attack.
The Syrian government says it would never resort to chemical weapons against Syrian citizens and in the past has accused rebels of doing so for battlefield advantage, an allegation Western leaders have dismissed.
Assad's government has suggested rebels may have carried out the latest attack themselves to provoke foreign intervention.
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