US Defense Secretary Jim Mattis asked all civilised nations to urgently unite in ending the Syrian civil war.
In London, Britain's Theresa May also emphasized that the retaliation was focused on Assad's chemical weapons and ensuring a stop to the "erosion of the worldwide norm that prevents the use of these weapons".
He stressed that missile strikes at Syria are "justified".
Bucci believes the retaliation has the potential to force Assad to forgo the use of chemical weapons.
"In July 2017 and in March 2018, the European Union imposed additional restrictive measures on Syrian high-level officials and scientists for their role in the development and use of chemical weapons and is ready to consider imposing further measures going forward". Explosions lit up the skies over Damascus, the Syrian capital, as Trump spoke from the White House.
May authorized the strikes without a vote from Parliament, which has been in recess. She said speed was essential and that military action was in the national interest.
Fresh Taliban attacks kill at least 13 policemen in Afghanistan
The attackers planted mines to prevent government reinforcements from coming and quickly took responsibility for the attack. The attack was the deadliest by the Taliban for several weeks.
Western powers carried out their biggest attack on Assad's regime before dawn on Saturday with strikes on targets they said were linked to Syria's chemical weapons program.
Britain has accused Russian Federation of being behind last month's nerve agent attack on former spy Sergei Skripal and his daughter in Salisbury, southern England - a charge Moscow has denied.
"This amounts to a flagrant breach of global laws and principles, a violation of Syria's right to national sovereignty and territorial integrity", the Foreign Ministry said in a statement. Russian Federation said that the Western powers "cynically" carried out military action hours before a team from the Organisation for the Prohibition of Chemical Weapons was set to begin an investigation into the suspected chemical weapons attack in the town of Douma in Eastern Ghouta that sparked the intervention by the USA and its allies. Syria then shot down an Israeli F-16 fighter jet, the first Israeli plane lost to enemy fire in decades.
Turkey is a vocal critic of Assad's regime in Damascus and backed rebels fighting for his ouster bun recent months it has closely worked with Russian Federation for a political solution in Syria even though Moscow remains a chief ally of the regime.
Iran has been Syrian President Bashar al-Assad's most supportive ally against insurgents throughout the conflict. Syria denies responsibility and says it gave up its chemical arsenal.
The Iranian-backed Hezbollah guerrilla organization immediately published a denial on its Arabic-language affiliate Al-Manar news outlet, saying there was "no truth to the rumor" there had been an Israeli attack.
For Steven Bucci, a former senior Pentagon official and a visiting fellow at the Heritage Foundation, a Washington-based think tank, the USA president was "sending a message that this isn't just firing and forgetting and everyone drives home".