WASHINGTON - US President Barack Obama planned to provide an update to the American people on Saturday about his decisions on how to proceed in Syria amid preparations for a potential military strike.Obama was to appear in the White House Rose Garden at 1:15 p.m. EDT (1715 GMT) to deliver a statement. A White House official said his remarks were not an address about imminent military operations in Syria, but rather an update about his decisions on how to proceed in response to a Syrian chemical weapons attack Aug. 21 that US officials say killed 1,429 people.The remarks were prepared after Obama's top national security advisers gathered at the White House for talks, including Defense Secretary Chuck Hagel, Secretary of State John Kerry and Martin Dempsey, chairman of the Joint Chiefs of Staff. They were to give senators an unclassified briefing on the Syria situation in conference calls.Members of the House of Representatives are to receive a classified briefing on Sunday from White House officials, a notice from House Speaker John' Boehner's office said.Obama had insisted on Friday that he had made no final determination on whether to launch an attack against Syrian government targets, but on Saturday there was a sense that plans might be advancing amid a flurry of meetings and consultations.Crisis in Syria - full JPost.com coverageThe United States was prepared to act on its own, perhaps with France but without a broad international coalition, to underscore what Obama said was a brutal and flagrant violation of international norms against the use of chemical weapons. Susan Rice, Obama's national security adviser, said on Twitter that while there is no question the Syrian government used chemical weapons, the "question now is how to hold Syrian govt accountable, keep Assad from using CW again."A debate has raged for days in Washington among members of the US Congress over whether, or how quickly, Obama should take action. But with Obama promising a narrowly limited engagement and not an Iraq-type invasion, the White House was prepared to take the heat from opponents.Senator Carl Levin, a Democrat who chairs the Senate Armed Services Committee, said after consultations with administration officials that he was concerned a strike without broad participation would be of weakened value."I also urged the administration to send a powerful message to the Assad regime by immediately getting lethal aid to vetted elements of the Syrian opposition. Doing so can change the balance militarily and also contribute to a political solution in Syria," Levin said.Obama has broad legal powers to take military action. He has made clear he believes the United States must do something to hold the Syrian government accountable for the attack.RESERVATIONSBut US lawmakers have pushed for more information about Obama's intentions in Syria, with many expressing reservations about the cost and impact of potential strikes.On Saturday afternoon, top national security officials will hold unclassified conference calls with the Senate Democratic Caucus as well as the Senate Republican Conference, a White House official said. Secretary of State John Kerry and Hagel will participate, as well as Rice, Director of National Intelligence James Clapper, and Admiral James Winnefeld, vice chairman of the Joint Chiefs of Staff.The discussions follow the White House release of an unclassified intelligence assessment that said the government had "high confidence" that the Syrian government was responsible for the deadly Aug. 21 chemical weapons attacks in a dozen neighborhoods.Obama and Kerry said the United States could not ignore the attack, but have not said whether or when they plan to strike."So the primary question is really no longer, what do we know? The question is, what are we - we collectively - what are we in the world going do about it?" Kerry said in a televised address on Friday.Protracted and expensive wars in Afghanistan and Iraq have left Americans reluctant to get involved in Middle Eastern conflicts.Most Americans do not want the United States to intervene in Syria. A Reuters/Ipsos poll taken this week showed only 20 percent believe the United States should take action, but that was up from 9 percent last week.Obama and Kerry have said they recognize Americans are tired of war, and have emphasized that they do not plan an "open-ended" response and will not send US troops into the country.Late on Friday, defense officials said a sixth US warship has now been positioned in the eastern Mediterranean, near five US destroyers armed with cruise missiles that could soon be directed against Syria as part of a "limited, precise" strike.However, the officials stressed that the ship, with several hundred US Marines on board, was in the region for a different reason and was being kept there only as a precaution. There were no plans to put Marines on the ground as part of any military action against Syria, they said.Some lawmakers have said Obama should seek backing for the strike with a vote in Congress. "The American people I think really deserve that debate," said Barbara Lee, a California Democrat in the House of Representatives, in an interview with CNN.