US President Donald Trump has taken the first major military action of his presidency by ordering the launch of dozens of Tomahawk missiles at Syria in response to the gas attack this week that claimed the lives of more than 70 people.

“I ordered a targeted military strike on the airfield in Syria from where the chemical attack was launched,” Mr Trump said. “It is in the vital national security interest of the US to prevent and deter the spread or use of deadly chemical weapons.”

Speaking on Thursday night from Florida where he was hosting Chinese President Xi Jinping, Mr Trump said he had ordered the strike because Syrian President Bashar al-Assad had conducted a “horrible chemical weapons attack on innocent civilians” with a deadly nerve agent.

Two US Navy ships in the Mediterranean fired 59 Tomahawk missiles at 8.40pm EST. They were aimed at Shayrat air base — from where the US believes the gas attack originated — and were programmed to hit runways and aircraft in an effort to degrade the Syrian air force, said one official.

The Pentagon said initial indications showed the strike had “severely damaged or destroyed Syrian aircraft and support infrastructure and equipment at Shayrat airfield, reducing the Syrian government’s ability to deliver chemical weapons.”

But a Russian defence ministry spokesman on Friday questioned the US assessment and said only 23 of the missiles had reached the target, destroying six ageing jets that were under repair. The runway was also undamaged, Major General Igor Konashenkov said on Friday.

One US official said the strikes were designed to “deter further use of chemical weapons” and that the administration would watch to see the reaction. Rex Tillerson, secretary of state, cautioned against reading too much into the action. “I would not in any way attempt to extrapolate that to a change in our policy or posture relative to our military activities in Syria today,” he said.

The US strikes, which came before dawn in Syria, were launched as Mr Trump dined with Mr Xi, who had arrived in Florida for his summit with the US president. The action has overshadowed what was intended to be a frank discussion between the leaders about everything from their trade relationship to North Korea.

Local pro-government journalists in Syria said at least 14 Syrian jets had been destroyed. The Syrian army said the attack killed six people and caused extensive damage, adding that it would respond by continuing its campaign to “crush terrorism” and restore peace and security to all of Syria.

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The army command described the attack as an act of “blatant aggression”, saying it had made the US “a partner” of Isis and other “terrorist organisations”.

Syrian activists said on Friday that an air strike hit the town of Khan Sheikhoun, site of the alleged chemical weapons attack, after the US attack. The Syrian Observatory for Human Rights said it was not clear whether the plane was Syrian or Russian.

Activist Othman al-Khani, who lives in the town, said locals are concerned they may be targeted for revenge.

“People have been fleeing the town since the chemical attack and they will keep fleeing now, everyone here is worried that actually maybe we will be targeted even worse,” he said.

Shayrat is one of Syria’s largest airbases, 45km east of Homs city. Talal al-Barazi, governor of Homs, told Reuters it was “essential” for Syrian forces in their operations against Isis in the eastern desert areas around the city of Palmyra as well as gasfields in the area.

The US gave Russia some notice about the strikes, saying “US military planners took precautions to minimise risk to Russian or Syrian personnel located at the airfield”.

However, the Kremlin has condemned the US strikes as an act of aggression and a “violation of international law”.

Russian state news agencies on Friday said President Vladimir Putin regarded the military action as “an aggression against a sovereign state . . . under a far-fetched pretext”. Moscow has also demanded a UN Security Council meeting to discuss the US strike.

The military strikes received support from Republicans and some Democrats. John McCain, the Republican head of the Senate armed services committee, praised the move, saying Mr Trump had “confronted a pivotal moment in Syria and took action”.

Transcript © AFP . Donald Trump’s statement on strike The US president spoke briefly after US missiles hit Shayrat air base

Ben Cardin, the top Democrat on the Senate foreign relations committee, said it would “send a clear signal that the US will stand up for internationally accepted norms and rules against the use of chemical weapons”.

David Petraeus, former head of the CIA who also headed Central Command, which oversees US military operations in the Middle East, said it was “reassuring to see that swift action by the Trump administration is making Bashar al-Assad’s forces pay a price for their barbaric use of chemical weapons against innocent civilians”.

But some members of Congress raised concerns that Mr Trump had not sought Congressional authority for use of force when the US had not been attacked by Syria.

Robert Satloff, a Middle East expert at the Washington Institute for Near East Policy, said the strikes would be “convincing evidence that the Trump administration will play by a different set of rules than his predecessor, who was widely viewed as hands-off and disengaged in the Middle East” and that US allies would “take succour from the swift military action to punish Assad for his brazen use of chemical weapons”.

A satellite image from October last year shows the Shayrat airfield targeted by US missiles on Friday morning

On Friday, western leaders spoke out against the Syrian regime. In a joint statement German Chancellor Angela Merkel and French President François Hollande blamed President Assad for the chemical weapons attack and the subsequent US missile strike.

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In a carefully worded declaration that highlights the co-operation between the EU’s two leading powers, the leaders avoided any direct judgment of Mr Trump’s decision, saying President Assad bore “sole responsibility for this development.”

Michael Fallon, the UK defence secretary, called for parties in Syria to “redouble” efforts to reach a political settlement after the missile strike. But he suggested that further US air strikes would take place if Mr Assad used chemical weapons again. “That is the message we take from last night,” the minister told the BBC.

The UK has made clear it “fully supports” the strike against Mr Assad, in which it was not asked to participate. In 2013 the British parliament voted against military action, effectively tying the hands of then prime minister David Cameron.

Obama’s stance on Syria and chemical weapons: a timeline August 20 2012: The US warns President Bashar al-Assad’s regime not to use of chemical weapons in the Syrian conflict. “We have been very clear to the Assad regime that a red line for us is [if] we start seeing a whole bunch of chemical weapons moving around or being utilised. That would change my calculus. That would change my equation,” President Barack Obama tells a new conference in Stockholm. August 21 2013: A chemical weapon attack near Damascus, the Syrian capital, kills more than 1,400 people. Mr Obama says that “countries who violate international norms regarding chemical weapons need to be held accountable”, and Washington is expected to launch retaliatory strikes together with the UK. August 29, 2013: The British Parliament votes against military action in Syria. August 30 2013: Mr Obama decides against strikes against the Syrian government, saying he wants Congress to make the decision. September 14 2013: Together with Russia, the US negotiates a deal to remove most of Syria’s chemical-weapons stockpiles by mid-2014. A congress vote on military intervention in Syria was therefore averted. — Later, Mr Obama tells The Atlantic that he is “proud of this moment”. His decision was influenced by factors including the UK vote and the fact that UN inspectors were still on the ground in Syria. “Our assessment that while we could inflict some damage on Assad, we could not, through a missile strike, eliminate the chemical weapons themselves . . . What I would then face was the prospect of Assad having survived the strike and claiming he had successfully defied the US, that the US had acted unlawfully in the absence of a UN mandate, and that would have potentially strengthened his hand rather than weakened it,” Mr Obama says.

Additional reporting by Mehul Srivastava in Istanbul, John Reed in Jerusalem and Henry Mance in London

Follow Demetri Sevastopulo on Twitter: @dimi

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