Leaders from across the globe have condemned a suspected gas attack in Syria's Idlib province, in which 100 people are thought to have died.
Although the alleged attack has been described as a "war crime", "heinous" and "horrific", world leaders appear to remain divided on how to end the Syrian conflict.
Here is how a number of the key players have reacted to the alleged chemical attack:
:: UK Government
Boris Johnson said it "bears all of the hallmarks" of the Syrian government, adding that if it was proved to have been committed by the Assad regime "it would be another reason to think they are an absolutely heinous outfit".
The Foreign Secretary said he believes it is "unbelievable" that Bashar al Assad can remain Syrian president in the long-term "given what he has done to his people".
Theresa May echoed Mr Johnson and called for an investigation into the reports.
The Prime Minister said: "There can be no future for Assad in a stable Syria which is representative of all the Syrian people and I call on all of the parties involved to ensure we have a transition away from Assad."
In December 2015, MPs voted to authorise airstrikes against Islamic State in Syria - increasing the UK's role in coalition efforts.
Two years earlier, David Cameron was defeated in a vote on UK military strikes against the Assad regime .
:: US/Donald Trump
The White House described the suspected gas attack as "heinous", but has fallen short of offering a plan of action.
Instead, President Trump said atrocities in Syria "are a consequence of the past administration's weakness and irresolution".
He added that Barack Obama "did nothing" after promising in 2012 that the use or transport of chemical weapons in Syria was "a red line for us".
Initially, US Secretary of State Rex Tillerson refused to answer when asked by reporters about the alleged attack.
However, he later said Russia and Iran bear "great moral responsibility" for the deaths in Idlib.
Last week, Mr Tillerson was widely criticised after appearing to suggest the Trump administration would do nothing to remove Assad from office, saying that the leader's long-term status "will be decided by the Syrian people".
:: United Nations
The UN Security Council will hold an emergency meeting on Wednesday, following a request by Britain and France.
US ambassador Nikki Haley, the current council president, said members "are hoping to get as much information on the Syrian attack as we can".
However, it is unclear what the UN Security Council will be able to do, as its previous efforts to act have been blocked.
In February, Russia and China vetoed a UN resolution to impose sanctions on Syria over the alleged use of chemical weapons.
It was the seventh time Russia vetoed a UN Security Council resolution to protect the Syrian government.
Meanwhile, China has voted down six Security Council resolutions on Syria since the civil war began in 2011.
The suspected gas attack was a "test" of Donald Trump's position on the Syrian conflict, French foreign minister Jean-Marc Ayrault has claimed.
Mr Ayrault said the president's administration should make its policy clear when the UN Security Council meets on Wednesday.
Mr Ayrault added: "I told them that we need clarity. What's your position?
"The question is to know, yes or no, whether the Americans support a political transition in Syria, which means organising this transition, elections and that at the end of the process the question of Assad's departure is asked."
Speaking alongside Mr Johnson in London, German foreign minister Sigmar Gabriel said it is vital that information is collected about war crimes to ensure there are "consequences for the guys who are responsible".
He said: "We gave the Secretary General of the United Nations one million euros some weeks ago because he asked for funding the group of experts… which have the responsibility to collect information about war crimes.
"We very much support the idea of collecting all the information about war crimes because if not every other terrible dictator would learn a very dangerous lesson."
:: Syrian Observatory of Human Rights
Rami Abdurrahman, founder of the UK-based Syrian Observatory of Human Rights, told Sky News that Syrians "have become merely numbers" to world leaders.
He said: "The international community has not done anything to help the children and the citizens of Syria, even though there is no end to this killing."
:: World 'needs to stand up to Assad'
British surgeon David Nott, who regularly works in Syria, says leaders across the globe "need to stand up to President Assad".
He told Sky News: "I dealt with children that had been wounded in conventional strikes and very rarely did I expect to deal with children that had been involved in chemical weapons attacks.
"The world needs to stand up to what violations are occurring and just hold people responsible - and it's now time this happened."