Syrian civilians walk past the rubble of buil
Syrian civilians walk past the rubble of builAFP/Miguel Medina

The United States may launch strikes against the Syrian regime “as early as Thursday,” senior U.S. officials have told NBC News.

Other officials previously said that America is unlikely to attack in Syria before Sunday, when the United Nations delegation currently in the Syria leaves the country.

Over the past 48 hours U.S. leaders have held a whirlwind round of consultations with leaders from around the world, including Australian Prime Minister Kevin Rudd, French President Francois Hollande, and leaders in Jordan and Saudi Arabia.

The Obama administration has explicitly blamed Syrian President Bashar Assad for a chemical attack last week in which several hundred Syrian civilians were killed. On Monday, U.S. Secretary of State John Kerry said there was “undeniable” evidence that Syria’s leaders had used chemical weapons to kill civilians – a scenario that U.S. leaders previously defined as a “red line."

Syrian rebels are urging America to hit Assad.

“If there is no action, we are afraid that in the coming days, not coming weeks, Bashar will use chemical weapons and chemical materials against very wide areas and, I’m afraid, to kill maybe 20,000 or 30,000 more people,” rebel general Salim Idris told NBC.

While U.S. leaders have warned of possible military action, Russia has been urging caution. Russian President Vladimir Putin has reportedly disputed claims that there is evidence showing the Assad regime was behind the notorious chemical attack near Damascus – or even that the attack took place.

Russia and China have both cautioned against an attack on Syria without United Nations approval.

However, apparently recognizing that their objections may be overruled, Russian leaders have begun an operation to remove Russian citizens from Syria. An Ilyushin-76 jet landed in Latakia, Syria, on Tuesday with humanitarian aid, and will carry roughly 180 people who wish to leave the country on its return flight.

According to Russian officials, an estimated 30,000 people currently in Syria have Russian citizenship.

Israelis are preparing for the possibility of a dramatic escalation in the fighting in Syria, as well: demand for gas masks quadrupled this week as many rushed to be ready in case of war.