The U.S., France and Britain have been consulting about launching a military strike.
Earlier in the day, Bashar al-Jaafari, Syrian ambassador to the United States, said in NY that two investigating teams from the OPCW were scheduled to arrive in Syria within the next 24 hours.
British Prime Minister Theresa May holds an emergency cabinet meeting Thursday amid speculation she will back U.S. action against Syria, despite divisions in a country still haunted by its involvement in the US-led invasion of Iraq. Syrian activists, rescuers and medics said the attack in Douma killed at least 40 people, with families found suffocated in their houses and shelters.
There were also signs of a global effort to head off a risky conflict that could pit Russian Federation against the West.
The two abovementioned tweets written in two different periods of time indicate the contradiction in the words and behaviour of U.S. authorities, particularly the country's president.
Mrs May has said "all the indications" are that the Syrian regime of president Bashar al-Assad, which denies mounting a chemical attack, was responsible.
"We have selections to earn good time, even once we determine that it is most useful and most efficient", he said, talking to prospective military strikes, and adding that any strikes will aim the regime's compound infrastructure.
However, he said this would anger some, including Labour leader Jeremy Corbyn, who believes parliament should be consulted first.
Assad warned on April 12 that threats of Western military action "will only contribute to further destabilization in the region". A special hotline for the United States and Russian militaries to communicate about operations in Syria was being used by both sides, Moscow said on Thursday.
Trump was responding to a Russian warning on Tuesday that any USA missiles fired at Syria over the assault on a rebel enclave would be shot down and the launch sites targeted.
World stocks edged down as anxious investors stayed wary of risky assets.
Voters from all main parties were overall against launching cruise missile attacks, but the majority (51 per cent) of 2017 Labour voters oppose the move while the Tories are nearly evenly split (33 per cent support strikes, 34 per cent oppose).
He added that Russian forces would retaliate against the source of any attacks. Moscow said that this was a "significant event in the history of Syria", meaning that the whole of Eastern Ghouta had come under the control of government forces. A U.S. Navy guided missile destroyer, the Donald Cook, departed Cyprus on Monday in the Mediterranean Sea.
The Syrian conflict has increasingly widened the rifts between Moscow, Washington and European powers and inflamed the bitter rivalries that run across the Middle East. A joint military operation, possibly with France rather than the U.S.in the lead, could send a message of global unity about enforcing the prohibitions on chemical weapons and counter Syria's political and military support from Russian Federation and Iran. He spoke during a meeting with Ali Akbar Velayati, an aide to the supreme leader of his ally, Iran.
Sanders said Trump would speak later with French President Emmanuel Macron and British Prime Minister Theresa May. We can not risk an escalation even further than it's gone'.
White House spokeswoman Sarah Huckabee Sanders says Trump held a meeting Thursday afternoon with his team to discuss the situation.
The United States and allies including France and Britain have been pushing for access to the Douma neighborhood where photos and videos show hundreds of children and adults seeking medical treatment from a reported gas attack.
Mr Davis suggested he had changed his mind since he voted against Syrian intervention in 2013 when David Cameron was prime minister. That then deterred the US administration of Barack Obama from similar action.