The former Ukip leader, who was the first British politician to meet the American leader following his election win, questioned why Syrian President Bashar al-Assad would “risk everything” by carrying out a chemical attack.
The US action on the Sharat airbase in Homs comes after a chemical attack in Idlib last week, which killed at least 80 people.
Speaking on his LBC show, Mr Farage said: “Why on earth would Assad, given that he was winning the war, given that the international community had eased the pressure off him massively over the course of the last 18 months, why on earth would he risk all of that, dropping chemical weapons? In what were actually limited numbers.
“He didn’t kill fives and tens of thousands with it, he killed 80 people with it. Why risk everything for that? It’s never made sense to me.”
Nigel Farage called Donald Trump's airstrikes into question on LBC
He didn’t kill fives and tens of thousands with it, he killed 80 people with it. Why risk everything for that? It’s never made sense to me
The MEP spoke out against Mr Trump’s move as the US secretary of state Rex Tillerson held talks with Russian President Vladimir Putin – a key ally of the Syrian government.
Mr Tillerson said there was a “low level of trust” between America and Russia following talks with Russian foreign minister Sergei Lavrov.
Russia and Syria both deny Assad’s involvement in the chemical attack as tensions continue to grow.
Mr Farage called for an investigation into the attack.
NATO meets Donald Trump months after he described it ‘obsolete’ Wed, April 12, 2017
The White House says the President will use the meeting as an opportunity to reaffirm his commitment to NATO
REUTERS 1 of 7
Get Quotes on Home Insurance
U.S. President Trump meets with NATO Secretary General Stoltenberg at the White House in Washington
Nigel Farage speaking during a Donald Trump campaign rally last year
He said: “Perhaps I'm assuming that Syrian dictators operate on the basis of logic and perhaps I'm completely wrong.
“But I have to say I do rather agree with Sergei Lavrov, let's have an investigation, let's send in the United Nations or someone like that and let's find out the truth.”
Mr Trump has claimed the Syrian government was responsible for the chemical attack.
After the US airstrikes, he said it was in the “vital national security interests” of the US to “prevent the spread and use of chemical weapons”.
He said: ”There can be no dispute that Syria used banned chemical weapons, violated its obligations under the Chemical Weapons Convention and ignored the urging of the UN Security Council."