Russian lawmakers have warned the United States that Moscow would view an airstrike on Syria as a war crime and that it could trigger a direct U.S-Russian military clash.
The United States accused the Syrian government on Friday of using banned chemical arms at least 50 times since Syria's civil war began seven years ago - far higher than the number of attacks that had been publicly confirmed.
Assad's main ally Russian Federation has repeatedly issued warnings to the U.S. that it will shoot back at missiles, warships and jets if they strike against Syria, bringing the United States and Russian Federation into direct conflict for the first time.
Sanders adds that US officials are "continuing to assess intelligence" and are "engaged in conversations with our partners and allies".
Trump has claimed that Syrian President Bashar al-Assad's administration has used chemical weapons. USA officials have been consulting with France, Britain and other allies on a possible joint military operation, but the timing remained in doubt Wednesday.
In an early morning tweet and later in comments at the White House, Trump attempted to cloud the timing of military action - a day after indicating it was imminent - and said a final decision had not yet been made.
Brexit Secretary David Davis said: "It is a very, very delicate circumstance, and we've got to make this judgment on a very careful, very deliberate, very well thought-through basis, knowing exactly ... how strong the evidence is". Then Thursday he tweeted that an attack on Syria "could be very soon or not so soon at all!"
Brooklyn holocaust survivors share stories of survival on remembrance day
Claims Conference President Julius Berman expressed concern about the lack of knowledge about the Holocaust among millennials. Poland, Israel and the USA on Wednesday mark Holocaust Remembrance Day with a ceremony at the U.S. state department.
"Syria's Foreign Ministry said Wednesday that Trump's threats to attack are "reckless" and endanger worldwide peace and security".
Macron said Thursday that France has proof the Syrian government launched chlorine gas attacks and said France would not tolerate "regimes that think everything is permitted".
Syria warned that it will have "no other choice" but to defend itself if the West launches military action. Trump on Wednesday had warned Russian Federation to "get ready" for a missile attack on its ally Syria.
Echoing the United States stance, France said Assad's government had reached a "point of no return" with repeated use of chemical weapons. The Syrian government has denied the allegations.
The British leader's office said Cabinet ministers "agreed on the need to take action to alleviate humanitarian distress and to deter the further use of chemical weapons by the Assad regime".
France already has some 1,100 troops involved in its Operation Chammal, created in 2014 to fight Islamic State extremists in Iraq and extended in 2015 to Syria, as part of the USA -led coalition.
A UN-led panel has determined that Assad's forces had used sarin in the town of Khan Sheikhun last yaer and chlorine in at least three attacks on villages in 2014 and 2015.