Boris Johnson has hinted at further air strikes against the Syrian government, saying he hopes the West “does not stand idly by” if incontrovertible evidence emerges of further chemical weapons use.
The Foreign Secretary spoke of Britain’s “failure” to take action in 2013, when MPs rejected military action against President Bashar Assad.
It came as Labour MP John Woodcock said the bodies from the latest violence in Syria “should be piled up in this chamber” as he urged ministers to do more.
Eastern Ghouta, a suburb of the capital Damascus, has been under intensive bombardment by government forces, backed by Russia, for weeks.
UN chief Antonio Guterres has denounced the violence in the embattled region, describing it as “hell on Earth”.
Answering an urgent question in the Commons from Mr Woodcock, Mr Johnson was asked by Tory MP Jack Lopresti about the use of chemical weapons in Syria and the possibility of limited strikes on the Assad regime.
The Foreign Secretary said: “I think that many people in this country will certainly share his sentiments and I think many people believe that the United States of America did exactly the right thing when they responded to the abomination of the attack at Khan Sheikhoun in April with the strike at the Shayrat airfield.
“I think that it is certainly the case that if the OPCW (Organisation for the Prohibition of Chemical Weapons) produces incontrovertible evidence of further use of chemical weapons by the Assad regime or their supporters, then I will certainly hope very much that the West does not stand idly by.”
The latest round of violence has included fresh reports of chlorine gas use, as well as indiscriminate bombing and the targeting of hospitals.
“The men and women of Ghouta who lie in pieces, deliberately targeted by Assad’s Russia-enabled bombs, the dead children whose faces are altered by the chlorine gas that choked them,” Mr Woodcock said.
“They should not be strewn in the rubble of eastern Ghouta. Those bodies should be piled up in this chamber and lain at the feet of governments of every single nation which continues to shrug in the face of this horror.”
He added that the UN Security Council “is broken while one of its permanent members flouts the basic laws and systems of order it was created to uphold”.
“In these dreadful circumstances, being cowed into inaction by this strangulated body is a greater violation than seeking to act even without its own authorisation.”
Mr Johnson, in response to the Labour MP for Barrow and Furness, said: “On his central point – which is that we in this country, the West, in the end did not do enough to turn the tide in Syria, that we missed our opportunity in 2013 – no one can conceivably contradict him.
“I think that we all understand what took place in the gap that we allowed to be opened up for the Russians and the Iranians to come in and to support the Assad regime. We all understand the failure that took place then.”
Mr Johnson said it was “almost impossible” for the Syrian regime to now achieve a military victory.
“The only way out of this mess, this morass, for the Russians is to go for a political solution,” he added.
Mr Johnson later said he “would like to see us be in a position to do something – not to allow the use of chemical weapons to go unpunished” after he was asked whether Britain would take action.
He added: “Let us not let the people of Syria down again.”
He said he had not spoken to Vladimir Putin in recent days, but told MPs that Prime Minister Theresa May was in “regular” contact with the Russian president and has “repeatedly made clear the view of the British Government”.
He also dismissed a suggestion by Tory Bob Seely (Isle of Wight) that “chemical munitions are now an accepted weapon of war in the modern era” because of their regular use in the last few years.
Mr Johnson earlier called for anyone found responsible for using chemical weapons in Syria to be held accountable, following reports of chlorine gas use in eastern Ghouta.
Shadow foreign secretary Emily Thornberry called the indiscriminate bombing in Syria and the use of chemical weapons a war crime, adding there “must be a reckoning for those responsible”.