The prime minister has defended her decision to send British forces to join USA airstrikes on Syria without consulting MPs, describing the chemical weapon attack in Douma as "utterly haunting".
The OPCW has recorded more than 390 allegations of chemical weapons use in Syria since its investigation began in 2014, Wilson said.
In a statement, the African Union said it "strongly condemns any use of chemical and other weapons prohibited under global law".
May was taking questions in Parliament about her decision to authorize the joint strikes.
The strikes came after the Assad regime was accused of carrying out a chemical attack in Syria's Douma, which killed 78 civilians and injured hundreds of others.
Mr Johnson, speaking at a summit of European Union foreign ministers, stressed it was "not an attempt to change the tide of the war in Syria or to have regime change" and "the Syrian war in many ways will go on in its awful, miserable way".
Both British Prime Minister Theresa May and French President Emmanuel Macron faced anger yesterday from their lawmakers for conducting the air strikes with the United States.
Syrian activists said more than 40 people were killed but Syria and Russian Federation deny the attack and Russian Federation even accused Britain of staging the attack.
Moscow said none of the more than 100 missiles targeted its bases and it did not activate its air defenses, despite threats earlier in the week that it would shoot down missiles and the platforms from where they were launched.More news: Jamie Oliver's restaurants go under down under
But, MPs did not get to vote on whether they approved of the decision to attack Syria's chemical weapons facilities. The mechanism would look at cases where the OPCW fact-finding mission has established chemical weapons were used or likely used.
The airstrikes received extreme backlash from Russian Federation, an ally of Assad's regime.
"From the point of view of al-Assad, Iran and Russian Federation, the real action of this war is happening on the ground and on the ground al-Assad is winning", said Landis.
Sayyed Hassan Nasrallah said the United States military had kept its strikes limited because it knew a wider attack would spark retaliation from Damascus and its allies and inflame the region.
Both Syria, which denies any chemical use, and Russian Federation, which provides military support to the Syrian government, have reacted angrily to the action.
Hassan Nasrallah, the leader of the Lebanese Hezbollah movement, which fights alongside the Syrian army, said the USA military had kept its strikes limited because it knew a wider attack would spark retaliation from Damascus and its allies and inflame the region.
According to Heller, "there are ways the Syrian government and its allies can make it more hard or less tenable for the United States and its coalition to operate inside Syria", including possibly Russian Federation using its air defenses to limit U.S. airpower.
Shouts of "Allah, Syria, and only Bashar", a reference to Syrian President Bashar Assad, rang out.
The U.S. -led strikes did nothing to alter the strategic balance or dent Assad's supremacy and the Western allies have said the aim was to prevent the further use of chemical weapons, not to intervene in the civil war or topple Assad.