Donald Trump’s daughter persuaded him to strike targets in Syria, according to reports of a diplomatic memo.

A cable briefing to Theresa May and Foreign Secretary Boris Johnson by Britain’s ambassador to Washington Sir Kim Darroch said Ms Trump was influential in bringing about the bombings, those who saw the memo said.

It claimed Mr Trump was “genuinely shaken” by pictures of more than 80 who died in a Sarin nerve gas attack that were broadcast on cable television, according to The Sunday Times.

Sources who read the message said the first daughter's position on the atrocity was a “significant influence in the Oval Office”. Ministers were told it meant the administration’s reaction was “stronger than expected”.

Sir Kim reportedly pointed to a tweet sent by Ms Trump in which she announced she was “heartbroken and outraged by the images coming out of Syria following the atrocious chemical attack”.

Marking a striking U-turn from the anti-interventionist stance Mr Trump took during his campaign, on Friday he ordered the firing of 59 cruise missiles at a military target in the war-torn country.

Reports said the barrage of Tomahawk missiles, fired from two US Navy vessels located in the Mediterranean Sea, targeted Al Shayrat air base in the central city of Homs, from which Syrian aircraft staged Tuesday’s chemical weapons attack.

In pictures: US missile strike against Syria Show all 7 1 /7 In pictures: US missile strike against Syria In pictures: US missile strike against Syria The guided-missile destroyer USS Porter (DDG 78) launches a tomahawk land attack missile in the Mediterranean Sea AP In pictures: US missile strike against Syria The United States military launched at least 50 tomahawk cruise missiles at al-Shayrat military airfield near Homs, Syria, in response to the Syrian military's alleged use of chemical weapons in an airstrike in a rebel held area in Idlib province EPA In pictures: US missile strike against Syria Shayrat airfield in Syria Getty Images In pictures: US missile strike against Syria US Navy guided-missile destroyer USS Ross (DDG 71) fires a tomahawk land attack missile in Mediterranean Sea Reuters In pictures: US missile strike against Syria US Navy guided-missile destroyer USS Ross (DDG 71) fires a tomahawk land attack missile in Mediterranean Sea Reuters In pictures: US missile strike against Syria President Donald Trump speaks at Mar-a-Lago in Palm Beach, Fla., after the US fired a barrage of cruise missiles into Syria in retaliation for this week's gruesome chemical weapons attack against civilians AP In pictures: US missile strike against Syria Syria's President Bashar al-Assad Reuters

After the missile strike, Ms Trump wrote on Twitter: “The times we are living in call for difficult decisions. Proud of my father for refusing to accept these horrendous crimes against humanity.”