The global chemical weapons watchdog said on Tuesday it will send a factfinding mission to the Syrian town where a suspected gas attack took place over the weekend, after receiving a request from the Syrian government and its Russian backers to investigate the allegations.
At the public meeting, Haley said, "The world must see justice done", adding that the United States would respond to the chemical weapons attack in Syria regardless of whether the Security Council acted or not.
Boris Johnson has criticised Russian Federation after it vetoed an American-drafted resolution at the United Nations to create a new body to determine responsibility for the suspected Syria chemical weapons attack.
U.S. President Donald Trump Monday warned of a quick, forceful response once responsibility was established.
After facing severe criticism of Russian Federation from fellow Security Council members, Russia's U.N. Ambassador Vassily Nebenzia slammed the US and other members for "fishing in the murky waters" of the Middle East, causing further chaos there.
Moscow opposes any Western strike on its close ally Assad and has vetoed Security Council action on Syria 12 times since the conflict started.
"From what we hear now, I am afraid they are looking for a military option, which is very, very unsafe", Nebenzia said.
The UN on Monday admitted its "feeble condemnations and paralyzed Security Council" in the wake of a deadly chemical attack in Douma, Syria, that reportedly killed dozens of civilians including women and children. And one thing it's trying to figure out is whether the chemical used in the attack was chlorine or a nerve agent.
Russian Ambassador Vassily Nebenzia said the US-drafted measure "contains some unacceptable elements, which make it worse" than a previous U.S. proposal put forward in March.
Asked if the United Kingdom would join any US-led military action in Syria, Mrs May said during a visit to Sweden: "What we are now doing is working urgently with our allies to assess what has happened here".
She said discussions were ongoing over a possible military response by Britain and its allies that would prevent "repeats".
After more than seven years of war, some 5 million people have fled to neighboring states, including around 1.3 million to Jordan, and an estimated 6.3 million are displaced from their homes across Syria.
But neither Trump nor Obama is guilty of violating the military principle of surprise, which is critical to the success of an operation, military experts said.
President Donald Trump has canceled a foreign trip to manage the crisis, which is testing his vow a year ago to stop Syrian President Bashar Assad from using chemical weapons against his own people. But if the USA finds that a nerve agent such as sarin was used instead of chlorine, or if nerve agents were mixed in with chlorine, retaliatory attacks against Assad regime targets may be bigger and more severe.
The Syrian government and Russian Federation say the reports are bogus. It was not immediately clear whether that visit would delay or avert USA or allied military action.
Mrs May sidestepped a question on whether Parliament would be recalled from recess to debate any military intervention. "For this particular strike, (secrecy) doesn't matter that much". "The team is preparing to deploy to Syria shortly".
Assad regime forces struck targets in Eastern Ghouta's Douma district on Saturday midnight, using a toxic gas which left at least 78 civilians dead, according to Syrian Civil Defense, also known as the White Helmets.
But both Syria and Russian Federation insist the attack did not happen and that graphic photographs of the victims were staged. Any plan by Washington and its allies to take military action was likely to be on hold until then, the source said.
Meanwhile on the ground, thousands of militants and their families arrived in opposition-held northwestern Syria after surrendering Douma to government forces.
"I think they were both stating policy objectives and positions" without giving away secrets that would help the enemy defend against an attack, Barbero said. TASS news agency quoted him as saying he believed common sense would prevail.
USA and French forces have reportedly moved to the eastern Mediterranean in anticipation of the strikes. The Aquitaine is equipped with 16 cruise missiles and 16 surface-to-air missiles.