The countries along with other allies, issued a joint statement under a so-called "Joint Command Centre", that also said the US attack had crossed a “red line” and added that “we will respond to any aggression.”
The statement, published on media outlet Ilam al Harbi said: "What America waged in an aggression on Syria is a crossing of red lines. From now on we will respond with force to any aggressor or any breach of red lines from whoever it is and America knows our ability to respond well."
The statement from the Joint Command Centre, which is made up of Russian, Iranian and the Lebannon's Hezbollah, said it would increase support to the Syrian army.
In addition the grouping called the US military presence in northern Syria as "illegal" and referred to the forces as an "occupation".
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World tensions are at fever pitch as Trump and Putin are at loggerheads over Syria
Iranian President Hassan Rouhani had earlier waded into the growing tensions between Russia and the US over the Middle East by saying the US had used “flagrant aggression on Syria.”
The Iranian leader, which has in the past supported Syria and Russia’s involvement in the country, condemned the US missile strike on a Syrian air base as well as launching an attack on the Gulf states that has supported the action sanctioned by US President Donald Trump.
Mr Rouhani called for an impartial investigation of the suspected chemical weapons attack in Syria which killed at least 70 people, and he warned that the US strikes in response risked escalating extremism in the region, during a televised broadcast.
In a phone call with Syrian counterpart Bashar al-Assad, Mr Rouhani told him: "Allegations that Syria launched the chemical attack were just a pretext to disrupt the Syrian peace process", according to a Press TV report.
The Kremlin said the phone call took place on Iran's initiative.
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Following news of the attack, celebrities and politicians expressed their thoughts on social media
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Trump ordered a massive military strike against a Syria
The Syrian state news agency SANA said Mr Assad told Mr Rouhani the Syrian people and army were "determined to crush terrorism in every part of Syrian territory" – a reference to rebels and militants fighting his rule for six years – and thanked him for Iran's support for "the Syrian nation".
In a speech on Sunday, Rouhani also criticised US-allied Gulf Arab states for endorsing the US missile strike.
Russian President Vladimir Putin
Rouhani said in remarks carried by state television: “Unfortunately, there are countries in our own region which encourage America's acts of aggression. Your turn will come too."
Saudi Arabia hailed the strike as a "courageous decision" by Mr Trump and a Saudi ally, the United Arab Emirates echoed that support.
Both countries belong to the US-led coalition fighting Islamic State militants in Syria.
US President Donald Trump (L) with Chinese premier Xi Jinping
The US launched a cruise missile attack on Friday against a Syrian airbase in response to a chemical weapons attack which killed 87 people including 31 children and which Washington says was carried out by the Syrian government.
Mr Assad's government has denied any involvement in the attack in the town of Khan Sheikhoun in the rebel-held Idlib province.
Syria's ally Russia says the deaths were caused when a Syrian air strike hit a depot where rebels were making chemical weapons, leading to a leak of toxic gas.