The Assad administration gave an official response condemning Thursday night's US actions on the Al-Shayrat airbase in a statement on Friday morning.
The official SANA News agency said the country's government saw the airstrikes as a "reckless and irresponsible act that only reflects a short-sightedness, a narrow horizon, and a political and military blindness."
"In an unjust and arrogant aggression, the United States targeted at dawn on Friday the airport of al-Shairat in the countryside of Homs,” a statement attributed to office of President Bashar al-Assad said.
The Russian government has historically been one of the main allies of the Syrian government, and has provided significant military support to President Bashar al-Assad's forces in the country's civil war.
Moscow had denied the Syrian government was behind Tuesday's chemical attack, which spurred the Trump administration into action.
Following the airstrikes overnight Thursday, President Vladmir Putin issued a statement via his press service condemning the US's actions, adding it would further damage already frayed bilateral relations between the two countries:
The President of Russia regards the US airstrikes on Syria as an act of aggression against a sovereign state delivered in violation of international law under a far-fetched pretext. The Syrian Army has no chemical weapons.
The fact of the destruction of all Syrian chemical weapons’ stockpiles has been recorded and verified by the OPCW, a specialized UN body. Vladimir Putin believes that complete disregard for factual information about the use by terrorists of chemical weapons drastically aggravates the situation.
This move by Washington [the US airstrike on an air base in Syria] has dealt a serious blow to Russian-US relations, which are already in a poor state. Most importantly, this move will not bring us closer to the ultimate goal of combatting international terrorism but will instead create a major obstacle to the establishment of an international counterterrorist coalition and to effective struggle against this global evil, something that US President Donald Trump declared as one of his main goals during his election campaign.
Vladimir Putin regards the US strikes on Syria as an attempt to draw public attention away from the numerous civilian casualties in Iraq.
Russian defense ministry spokesman Maj. Gen. Igor Konashenkov said Friday that the country’s military would take a “complex of measures” to bolster Syrian air defenses in the wake of the strikes, in order to “protect the most sensitive Syrian infrastructure facilities,” AP reported.
Iran is another ally of the Assad regime, it's Foreign Ministry strongly condemned the US's actions in Syria in a statement provided to the official IRNA news agency.
"Tehran considers this excuse for unilateral action as dangerous, destructive and violation of fundamental principles of international law," ministry spokesman Bahrem Qasemi said.
"Iran believes that such measure under the pretext of alleged use of chemical weapons in Khan Shaykhun which its timing, perpetrators and beneficiaries are all suspected would not only complicate the situation in Syria but in the entire region."
Iran "won't be quiet" after the US attack in Syria, Allaeddin Boroujerdi, the head of parliamentary committee on national security and foreign policy, told Iran's parliament news agency, ICANA.ir, the Associated Press reported.
"Russia and Iran won't be quiet against such acts which violate interests of the region," Boroujerdi was quoted as saying, adding that serious consequences would follow US action, the AP reported.
In a series of tweets, Iran's Foreign Minister Javad Zarif said that the country "condemned use of all WMD by anyone against anyone."
"Not even two decades after 9/11, US military fighting on same side as al-Qaida & ISIS in Yemen & Syria," Zarif tweeted. "Time to stop hype and cover-ups."
A spokesperson for British Prime Minister Theresa May has described the air strikes as an "appropriate" response to Tuesday's chemical attack.
"We believe [it] was an appropriate response to the barbaric chemical weapons attack launched by the Syrian regime, and is intended to deter further attacks."
"Overnight, the US has taken military action against the Syrian regime, targeting the airfield in Shayrut which was used to launch the chemical weapons attack earlier this week," the spokesperson said, according to the BBC.
Read more about the reaction in the United Kingdom here.
France and Germany
French President François Hollande and German Chancellor Angela Merkel issued a joint statement condemning the chemical attack on Friday morning, saying Assad bears “full responsibility” for developments overnight on Thursday, but stopped short of explicitly endorsing the Trump administration’s airstrikes.
They said the two nations would continue to work within the UN framework to punish the regime “in the most appropriate way,” and called for nations to come together “to hold President Assad responsible for his crimes.”
The leaders said they had been informed of the strikes by Washington in advance.
Australian Prime Minister Malcolm Turnbull accused Assad of a "shocking war crime", saying it deserved the "swift response" from the US military.
"More than 70 people were killed in horrific circumstances," Turnbull said at a Sydney press conference.
"Civilians, women, children, babies – it was a crime that called out for a swift response.
"We can say that the Australian government strongly supports the swift and just response of the United States."
Read more about the reaction in Australia here.
Israeli Prime Minister Benjamin Netanyahu issued a statement praising the Trump administration's airstrikes: “In both word and action, President Trump sent a strong and clear message today that the use and spread of chemical weapons will not be tolerated,” he said.
An Israeli defense official told BuzzFeed News they welcomed the action, and said both it and Jordan had been notified beforehand.
"There need to be lines drawn as to what is accepted and what is not. Assad needs to understand what those lines are. It is good for the world — especially our part of the world — to see the US president take decisive action," the official said.
Saudi Arabia — one of the main US allies in the Middle East — has praised Trump's actions in Syria.
The country's state SPA news agency quoted an official government source as saying the kingdom gave its "strong support for the military operations carried out against military targets in Syria".
Other Sunni majority US allies in the region have also expressed support for the airstrikes, according to the Financial Times.
A spokesman Turkish President Recep Tayyip Erdogan praised the airstrikes on Friday morning, and said that a no-fly-zone should be urgently established.
"We view the U.S. missile strike carried out this morning against Shayrat air base in Homs, Syria as a positive response against the war crimes of Assad," Ibrahim Kalin said in a written statement to the semi-official Andalou Agency on Friday.
"A no-flight zone and safe haven should be realized urgently in order to prevent similar massacres," he added.
European Council president Donald Tusk praised the US's resolve and said the EU would work with Washington to end the "brutality" in Syria.
NATO Secretary General Jens Stoltenberg released the following statement following the US' actions:
The Syrian regime bears the full responsibility for this development. NATO has consistently condemned Syria’s continued use of chemical weapons as a clear breach of international norms and agreements.
Any use of chemical weapons is unacceptable, cannot go unanswered, and those responsible must be held accountable. NATO considers the use of chemical weapons as a threat to international peace and security.
NATO supports all international efforts aimed at achieving peace and a political solution in Syria.
United Arab Emirates
The United Arab Emirates (UAE) expressed its "full support" to the US strikes in Syria. In a statement, the Ministry of Foreign Affairs said, "The attack on the civilians is a continuation of the heinous crimes committed by the regime against the Syrian people. It is a blatant violation of international and humanitarian conventions."
Dr. Anwar bin Mohammed Gargash, the Minister of State for Foreign Affairs, praised the "courageous and wise decision" of Trump and said that it strengthened the US's position" after the failure of the UN Security Council to play its role in the protection of international peace and security.
"It reflects the determination of the US President to respond decisively to the crimes of this regime, the minister said.
Bahrain supported the military operation by the US, the Ministry of Foreign Affairs said in a statement published by Bahrain's state news agency.
"Bahrain affirms that such a step was needed to stop the bloodshed and prevent the proliferation or use of any banned weapons against innocent civilians," the statement said. The ministry also said it "praises" Trump's remarks "which reflect the United States determination and strong will to defeat terrorism in all its forms."
In a statement, Prime Minister Justin Trudeau said that Canada "fully supports the United States’ limited and focused action to degrade the Assad regime’s ability to launch chemical weapons attacks against innocent civilians, including many children."
Trudeau said that Assad's use of chemical weapons and "gruesome attacks" against his own people could not be ignored.
"This week’s attack in southern Idlib and the suffering of Syrians is a war crime and is unacceptable," Trudeau said. "Canada condemns all uses of chemical weapons."