This is an archived article that was published on sltrib.com in 2013, and information in the article may be outdated. It is provided only for personal research purposes and may not be reprinted.

Washington • U.S. intelligence officials sought Saturday to determine whether Syria's government unleashed a deadly chemical weapons attack on its people. At the same time, the Obama administration prepared for a possible military response by moving naval forces closer to Syria.

Meeting on the issue Saturday with his national security team, President Barack Obama received a detailed review of the range of options he has requested for the U.S. and its international partners to respond if the fact-finding process concludes that Syrian President Bashar Assad engaged in deadly chemical warfare, the White House said.

At the same time, Obama has emphasized that quick intervention in the years-old Syrian civil war was problematic because of the international considerations that should precede a military strike.

Obama discussed the situation in Syria by telephone with British Prime Minister David Cameron, the White House said. It was Obama's first known conversation with a foreign leader about Syria since the reports this week that hundreds of Syrians had been killed by the alleged chemical attack in a suburb of Damascus, the capital.

The White House said the two leaders expressed "grave concern" about the reported chemical weapons use, which both of their countries oppose.

A statement from Cameron's office at No. 10 Downing St. said the prime minister and Obama "reiterated that significant use of chemical weapons would merit a serious response from the international community."

The Syrian government denies the claims. It also has warned the U.S. against taking military action.

Officials have said Obama will decide how to respond once the facts are known.

Defense Secretary Chuck Hagel declined Friday to discuss specific force movements while saying that Obama had asked the Pentagon to prepare military options for Syria. U.S. defense officials told The Associated Press that the Navy had sent a fourth warship armed with ballistic missiles into the eastern Mediterranean Sea but without immediate orders for any missile launch into Syria.

Navy ships are capable of a variety of military actions, including launching Tomahawk cruise missiles as they did against Libya in 2011 as part of an international action that led to the overthrow of the Libyan government.

Hagel said the U.S. is coordinating with the international community to determine "what exactly did happen" near Damascus. According to reports, hundreds were killed in a chemical attack in a suburb. It would be the most heinous use of chemical weapons since Iraqi leader Saddam Hussein gassed thousands of Kurds in the town of Halabja in 1988.

Hagel left little doubt that he thinks chemical weapons were used in Syria.

The United Nations disarmament chief, Angela Kane, arrived in Damascus on Saturday to press the Syrian government to allow U.N. experts to investigate the alleged chemical attacks.

Obama remained cautious about getting involved in a war that has killed more than 100,000 people and now includes Hezbollah and al-Qaida. He made no mention of the "red line" of chemical weapons use that he marked out for Assad a year ago, which U.S. intelligence says has been breached at least on a small scale several times since.

For a year now, Obama has threatened to punish Assad's regime if it resorted to its chemical weapons arsenal, saying use or even deployment of such weapons of mass destruction constituted a "red line" for him. A U.S. intelligence assessment concluded in June that chemical weapons have been used in Syria's civil war, but Washington has taken no military action in response.

U.S. officials have instead focused on trying to organize a peace conference between the government and opposition. Obama has authorized weapons deliveries to rebel groups, but none are believed to have been sent so far.

After rebels similarly reported chemical attacks in February, U.S. confirmation took more than four months. In this instance, a U.N. chemical weapons team is already on the ground in Syria.