President Hassan Rouhani stressed Iran's support for the Syrian state in "its war against terrorism" during a call with his counterpart Bashar al-Assad on Sunday, condemning a US missile strike on Syria as a violation of its sovereignty.
In commenting on the US missile attack, Prime Minister Shinzo Abe said the threat posed by weapons of mass destruction has become serious also in East Asia and said, "Japan highly values President Trump's strong commitment to maintenance of the worldwide order and to the peace and security of its allies and the world".
Johnson said: "Developments in Syria have changed the situation fundamentally".
Russian Federation also raised the specter of direct military confrontation with the U.S., warning that the American attack brought the two parties "within an inch" of war. "Under what law or authority did you launch your missiles at this independent country?"
The top USA diplomat, known as a man of few words, had harsh comments for Russian Federation, which Washington blamed for failing to rein in its ally, Syrian leader Bashar al-Assad. A joint command center made up of the forces of Russian, Iran and allied militia alliance supporting al-Assad said the USA strike on a Syrian air base crossed "red lines" and it would now respond to any new aggression and increase their level of support to their ally.
"The president believes that the Syrian government, the Assad regime, should at the minimum agree to abide by the agreements they made to not use chemical weapons", Spicer said when asked if Assad should step down. And Haley, too, said Washington's priority was "no longer to sit and focus on getting Assad out".
A USA official said all but one of the 59 missiles struck their targets, hitting multiple aircraft and air shelters, and destroying the fuel area.
He likened them to the claims that Saddam Hussein's regime had weapons of mass destruction which premised the US-led invasion of Iraq in 2003 but which later turned out to be baseless. USA officials say about 20 planes were destroyed in Friday's attack on the Shayrat base. Damascus has categorically denied carrying out a chemical attack.
A Pentagon spokesman says Russian forces in Syria were warned of the imminent missile strikes on the airfield so they could get out of harm's way.
The Iranian regime, another Syrian ally, "strongly condemned" the strike, just as it condemned "all unilateral military action".
But the facts concerning the suspected use of chemical weapons have yet to be fully clarified.
In the aftermath of the USA strike, Russian Federation pledged to help strengthen Syria's air defenses.
Foreign Secretary Boris Johnson has cancelled a visit to Moscow next week as tensions grow over events in Syria. He said Trump decided that the U.S. "could not yet again turn away, turn a blind eye" after Obama's inaction in 2013.
Media captionWATCH: What is President Trump's plan in Syria?
An attack on a rebel-held area in northwestern parts of Syria killed more than 100 people, including children.
In an address to the US Congress in February this year, Mr Trump spoke of relations with North Atlantic Treaty Organisation and indicated he did not want the US to act on behalf of the world's nations.
Trump officials on April 7 signaled new sanctions would soon follow the missile attack earlier in the day, and that the Pentagon was even looking into whether Russian Federation had a role in the chemical-weapons attack that prompted Washington to launch 59 cruise missiles in its first-ever assault against Assad's regime.
"Even handsome babies were cruelly murdered in this very barbaric attack", Mr Trump said.