Assad allies threaten reprisals as Trump mulls regime change

"The aggression against Syria oversteps all red lines. We will react firmly to any aggression against Syria and to any infringement of red lines, whoever carries them out," said a statement from the Syria-based joint operations room for regime backers Russia, Iran and allied forces including Lebanon's Hizballah.

"The United States knows very well our ability to react," said the statement published on the website of Al-Watan, a daily Syrian newspaper controlled by the regime.

On Friday, Washington carried out its first military action against Bashar al-Assad's government since the start of Syria's six-year war.

US warships in the Mediterranean launched a barrage of 59 cruise missiles at Shayrat airbase in Syria early on Friday, after 87 people including 31 children were killed in a suspected Syrian regime-sanctioned chemical attack on rebel-held Khan Sheikhun.

"We condemn any attack targeting civilians and also condemn what happened in Khan Sheikhun, even if we are convinced it was a premeditated act by certain countries and organisations to serve as a pretext to attack Syria," the Syrian statement added.

On Sunday, days after US military strikes, the US ambassador to the United Nations hinted the Trump administration was mulling regime change.

"There's not any sort of option where a political solution is going to happen with Assad at the head of the regime," Nikki Haley told "State of the Union" program. 

Much of the international community accused Assad's government of carrying out Tuesday's suspected chemical attack on Khan Sheikhun, but Damascus denied responsibility.

Following the chemical attack, Russian and Iranian army chiefs vowed to keep fighting alongside Bashar al-Assad against rebels they brand as "terrorists."

Syria's war has killed more than 320,000 people since it started in 2011 with the brutal repression of anti-government protests.

International rights organisations say the brutal tactics pursued mainly by the regime, which have included the use of chemical weapons, sieges, mass executions and torture against civilians amount to war crimes.