Spokesman Sean Spicer said the missile attack sent a clear message to Assad, but he avoided explicitly calling for the Syrian to leave office.
Rohani called the US strike a "blatant violation" of Syrian sovereignty while dismissing reports that Assad's regime was behind the deadly gas attack as "baseless".
"If this strike is not followed up by political, military and diplomatic pressure, it will give a chance to Assad to boast they have contained the strike and they have made an achievement", Hijab said at a pre-scheduled Friday morning event at the Atlantic Council.
"Our military destroyed the airfield from which this week's chemical strike took place".
Haley disagreed, telling Tapper that the United States government has evidence.
The United States is now likely to be more aggressive in pursuing intelligence about Syria's suspected chemical weapons program. He said it was ultimately "the regime's choice" if more USA military action would be needed.
Much of the global community rallied behind Mr Trump's decision in reaction to this week's chemical weapons attack that killed dozens of people in Syria. Tillerson is arriving at a fragile point in U.S. -Russia relations, where he will have to confront the Kremlin's anger over the missile strikes in Syria along with suspicion at home that Moscow may have been complicit in the Syrian government's chemical weapons attack.
"The moral stain of the Assad regime could no longer go unanswered".
"President Assad's use of chemical weapons and the crimes the Syrian regime has committed against its own people can not be ignored".
"It could be that the Assad regime is playing the Russians for fools", Haley said.
Russian Federation and Iran, Assad's chief allies, quickly condemned the strike in strong terms, while Washington's allies voiced support for the USA action.
"We strongly condemn the illegitimate actions by the US".
He said its "consequences for regional and global security could be extremely serious".
A visibly agitated Safronkov said Washington, London and Paris have a "paranoiac idea" of overthrowing the legitimate government in sovereign Syria.
Russia's United Nations representative Vladimir Safronkov said: "Stop putting forward these unprofessional arguments and accusations against my country".
"Don't even try to get into fights in the Arab world". That is why you are getting annoyed.
Safronkov called on the U.S. to "immediately cease" its aggression and join efforts towards a political settlement in Syria.
The Russian government has slammed the strikes as an act of aggression that has violated global law - on a "trumped-up" pretext according, to Kremlin spokesman Dmitry Peskov.
The United States is vowing to keep up the pressure on Syria after the intense nighttime wave of missile strikes from USA ships, despite the prospect of escalating Russian ill will that could further inflame one of the world's most vexing conflicts.
Short of that, the Syrian opposition is asking the Trump administration to use any new leverage it has to demand a nationwide ceasefire, to stop the killing of civilians by the Assad regime and press for global access to all besieged areas and the jails where Assad is holding thousands of civilians in custody.
The Western world has welcomed the direct US involvement, as have Saudi Arabia, Turkey, and Israel. Moscow is hoping that Trump will revive the relationship between the United States and Russian Federation. "The same applies to al-Qaida in Idlib", a province in northern Syria, Hijab said.
Citing the American claim that there were weapons of mass destruction in Iraq and its consequent military invasion in the country, Mounzer said the United States was once again using fabricated evidence to justify its actions and spread hegemony around the world.
"In no way do we see peace in that area with Russian Federation covering up for Assad". "Russia has failed in that commitment".
Russian Federation has repeatedly defended Syria against the accusation that Damascus has used chemical weapons. They also believe now is the time to push for a new political process to move Assad out of power.
The strikes against Shayrat Airfield in Homs Governorate were ordered by US President Donald Trump.
The United States is not at war with Syria - at least not yet.
Russian foreign minister Sergei Lavrov said the Americans had used a "far-fetched pretext" to justify the attack while the defence ministry in Moscow said it would be helping its Syrian ally strengthen its air defences.
"Both sides noted the inadmissibility of aggressive US actions against a sovereign state in violation of global law", the statement said. "Russia and Iran will not allow America to dominate the world".
Even after six years of war, the Syrian opposition and Syrian civilians are still crying out for the United States to lead the global charge to defend their dignity and basic rights, he said.
Security Council resolutions and the 2012 Geneva Communique remain the foundation of, and contain the core principles for, United Nations mediation efforts and ultimately a solution in this regard, he said. Despite intense global pressure, Assad has clung to power since a civil war broke out in his country six years ago, helped by financial and military support from both Russian Federation and Iran.
A statement from the Syrian General Command of the Army and the Armed Forces called the U.S. response a "blatant act of aggression" which had caused six deaths and huge material damage.