As international pressure mounts for action in response to chemical attacks alleged to have been perpetrated by the Assad regime, US officials say they could launch military strikes on Syria as early as Thursday.

From NBCNews.com:

The United States could hit Syria with three days of missile strikes, perhaps beginning Thursday, in an attack meant more to send a message to the Syrian regime than to cripple its military, senior U.S. officials told NBC News.

The disclosure added to a growing drumbeat around the world for military action against Syria, believed to have used chemical weapons in recent days against scores of civilians and rebels who have been fighting the government for two years.

In three days of strikes, the Pentagon could assess the effectiveness of the first wave and target what was missed in further rounds, the senior officials said.

Secretary of State John Kerry said Monday that the chemical weapons attack was undeniable and accused the Syrian government of the “indiscriminate slaughter of civilians,” according to the NY Times.  A United Nations team sent to investigate the site of chemical attacks came under sniper fire on Monday near the capital city of Damascus, causing a delay in their activities.

Reports from the Associated Press on Tuesday (via NPR) indicated that the Obama administration is expected today to formally declare that Assad’s regime launched a chemical weapons attack against his own people last week.  The AP also reports that following that statement, we are likely to hear about a planned US military response.

Defense Secretary Chuck Hagel said in an interview today that the US military is “ready to go, like that,” if ordered.

Meanwhile, France’s President Francois Hollande pledged more support today to Syrian government opposition, according to Agence France-Presse.

“France is ready to punish those who took the vile decision to gas innocent people,” he said in a televised speech, pointing the finger of blame at President Bashar al-Assad’s regime.

Hollande also said France would increase military support to Syria’s main opposition body.

“I have decided to increase our military support to the Syrian National Coalition,” he said in the speech.

In contrast, Russia’s foreign ministry warned in a statement today that military intervention from the US and its allies would result in “catastrophic consequences” for Syria and the region.

Russia has also begun evacuating from Syria about 100 Russians and 80 citizens of former Soviet countries who have “made clear a desire to leave the country,” according to ITV.