Obama has been considering a limited military strike against Syria, but he said Friday that he hadn't yet made a decision.
The strike would be in response to a chemical weapons attack the U.S. says Syrian President Bashar Assad's government carried out against Syrians. The U.S. says more than 1,400 Syrians were killed in that attack last week.
The White House is also briefing senators Saturday about Syria.
Obama's statement is set for 1:15 p.m. EDT Saturday.
WATCH IT LIVE FROM WHITEHOUSE.GOV
The United States is considering launching a punitive strike against the regime of Syrian President Bashar Assad, blamed by the U.S. and the Syrian opposition for an Aug. 21 alleged chemical weapons attack in a rebel-held suburb of the Syrian capital of Damascus. The U.S. said the attack killed 1,429 people, including at least 426 children. Those numbers are significantly higher than the death toll of 355 provided by the aid group Doctors Without Borders.
Here's a look at key Syria developments around the world Saturday amid heightened tensions over potential military action:
U.N. chemical weapons inspectors were believed to have arrived in the Netherlands. Samples the team collected during four days of on-site Syria visits are expected to be repackaged and sent to European laboratories. They will be checked for traces of poison gas that may have been used in the alleged chemical attack. The Organization for the Prohibition of Chemical Weapons, based in The Hague, was expected to receive blood and urine samples taken from victims as well as soil samples from affected areas.
Rebels fighting to topple Assad said they plan an offensive against his troops in attacks coinciding with any U.S. strikes. Syrian state TV showed images of Syrian soldiers training, fighter jets soaring in the sky and tanks firing at unseen targets, to the backdrop of martial music. The potential U.S. military strike dominated the station's morning talk shows.
Secretary of Defense Chuck Hagel and other officials arrived at the White House as Obama's national security team prepared to brief senators on Syria. Senior officials planned to consult by phone with Senate Democrats and Republicans.
President Vladimir Putin urged President Barack Obama not to rush a decision on striking Syria, and to consider whether strikes would help end the violence and be worth likely civilian casualties. Putin said Obama should reflect on the results of U.S. military intervention in Afghanistan and Iraq before deciding whether to launch air strikes against Assad's regime.
U.N. disarmament chief Angela Kane was scheduled to brief Secretary-General Ban Ki-moon on the investigation conducted by the experts into the alleged chemical attack.
Five U.S. Navy destroyers were in the eastern Mediterranean Sea waiting for the order to launch. The destroyers are armed with dozens of Tomahawk cruise missiles, which have a range of about 1,000 nautical miles (1,151 miles, 1,852 kilometers) and are used for precise targeting. French military officials confirmed the frigate Chevalier Paul, which specializes in anti-missile capabilities, as well as the hulking transport ship Dixmude were in the Mediterranean for training and operational preparations but denied any link to possible Syria operations.
Demonstrators opposed to military intervention in Syria burned U.S. and Israeli flags and chanted outside the American embassy in the Jordanian capital of Amman. Protester Kawthar Arrar said a strike would be “an aggression on the whole Arab world.”
Italian Premier Enrico Letta said his country understands why the United States and France are considering military action against Syria's regime, but said Italy cannot without U.N. backing. He said Italians are deeply disturbed by images of the alleged chemical weapons attack and the international community is having “difficult moments” trying to decide on an appropriate response to prevent future chemical attacks.
Nearly two-thirds of French people oppose military intervention by their country in Syria, according to a survey released by polling agency BVA. The Aug. 29-30 telephone survey polled 1,010 French people over age 18. It found that 64 percent oppose their country's participation in a possible military strike targeting Assad's regime. The margin of error was plus or minus 3 percent.