"It angers and saddens me that President Trump has taken the advice of war hawks and escalated our illegal regime change war to overthrow the Syrian government," Gabbard, the Democratic Congresswoman from Hawaii, said in a statement.
Gabbard is a Iraq war veteran and a member of the powerful House Foreign Relations Committee.
In January Gabbard travelled to Syria to meet Syrian President Bashar al-Assad, thus making her perhaps the only senior US official to meet the Syrian leader.
"This administration has acted recklessly without care or consideration of the dire consequences of the US attack on Syria without waiting for the collection of evidence from the scene of the chemical poisoning," Gabbard said.
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"If President Assad is indeed guilty of this horrible chemical attack on innocent civilians, I will be the first to call for his prosecution and execution by the International Criminal Court." she said.
Gabbard appeared to be the lone voice in opposing the Trump's decision to carry out missile strikes against the Syrian regime. Trump appeared to have bipartisan support to his military decision, which came in less than 100 days of him taking over the office of presidency.
On Trump's orders, US warships in the Mediterranean Sea launched between 50-60 Tomahawk cruise missiles at the Shayrat air base, in Homs governorate, where the warplanes that carried out the chemical attacks are based. The attack was in retaliation to a "barbaric" chemical attack on civilians allegedly by Assad's regime.
"Resolving the years-long crisis in Syria is a complex task, but Bashar al-Assad must be held accountable and his enablers must be persuaded to change course. I look forward to the administration further engaging Congress in this effort," Ryan said.
"Unlike the previous administration, President Trump confronted a pivotal moment in Syria and took action. For that, he deserves the support of the American people. Building on tonight's credible first step, we must finally learn the lessons of history and ensure that tactical success leads to strategic progress," said Senators John McCain and Lindsay Graham in a joint statement.
"Assad was warned, repeatedly, by the US and the UN that the intentional targeting of innocent men, women and children is intolerable," said Congressman Ed Royce, Chairman of the House Foreign Relations Committee.
"Now Assad has been caught red-handed carrying out another abhorrent chemical attack, and the administration has taken a measured response. Moving ahead, the administration must work with Congress and lay out clear policy goals for Syria and the region," Royce said.
Senator Dick Durbin said this was a measured response to the Syrian nerve gas atrocity. Senator Bob Corker, Chairman of the Senate Foreign Relations Committee applauded Trump for taking decisive action following the latest chemical weapons attack.
"These military strikes against Assad's arsenal send a clear signal that the United States will stand up for internationally accepted norms and rules against the use of chemical weapons," said Senator Ben Cardin.
House Democratic Whip Steny H Hoyer said the airstrikes, launched in response to the horrific atrocity of the use of chemical weapons, are not a sufficient answer on their own to the challenge posed by the civil war in Syria and the Assad regime's war crimes.
"Trump's decision to strike the Assad regime's air base where chemical weapons were deployed against the innocent people of Syria earlier this week sends a clear signal to the world that war crimes such as these will not be tolerated. I support the president's swift and decisive action to punish this dictatorship for the atrocities committed," said Senator Johny Isakson.
House Majority Leader Kevin McCarthy applauded US troops for their professionalism in carrying out these strikes.