"It's too bad that the world puts us in a position like that", said Trump, as Defense Secretary James Mattis headed to the West Wing to present options for a retaliatory strike.
The same officials say Syria has continued to produce or procure chlorine, which also has industrial and agricultural uses.
"Six in ten Brits (61%) say that it should be necessary for Parliament to vote first on whether the United Kingdom takes part in military action in Syria - 18% say it should not be necessary for Parliament to vote on the matter", the pollster wrote on Twitter on the results of its survey.
The White House and National Security Council did not immediately respond to Anadolu Agency's requests for comment on the report.
"What we've got here in Syria is a choice between monsters on the one hand and maniacs on the other", Julian Lewis, the chairman of the House of Commons defence committee, told the BBC. The Syrian government has been known to use chlorine bombs, along with sarin, a nerve agent developed by Nazi Germany that was used in a 2013 attack that killed almost 1,500 people outside of Damascus.
"France will shoulder its responsibility to end an intolerable threat to our collective security", said French Ambassador Francois Delattre, who called for an end to the "chemical weapons escalation in Syria".
"There has been no decision to take military action at this point".
"Cabinet agreed on the need to take action to alleviate humanitarian distress and to deter the further use of chemical weapons by the Assad regime", a spokeswoman for the prime minister said in a statement after the meeting.
More deaths in Gaza as protests continue
Some 350 Gazans were treated for injuries, including 59 from live fire, Palestinian authorities said. No Israeli soldiers or civilians have been wounded or killed during the protests in Gaza .
At the House hearing, Democrats grilled Mattis on the wisdom and legality of Trump ordering an attack on Syria without explicit authorization from Congress. Mattis argued it would be justified as an act of self-defense, with 2,000 US ground troops in Syria; he insisted he could not talk about military plans because an attack "is not yet in the offing".
Echoing the United States stance, France said Assad's government had reached a "point of no return" with repeated use of chemical weapons.
Peskov wouldn't say if Moscow could use a Russia-U.S. military hotline to avoid casualties in a case of a U.S. blow, saying only that "the hotline exists and has remained active".
"Until we have a more long-term strategy, until we have some idea where we're going in Syria and the Middle East, it seems unwise, to me, to start launching missiles", said Smith, D-Wash.
Trump has claimed that Syrian President Bashar al-Assad's administration has used chemical weapons.
"Just imagine the scenario if an American missile shoots down a Russian plane, or vice-a-versa - where do we go from there?"
Trump posted a tweet on Wednesday warning Russian Federation to "get ready" because missiles "will be coming" to Syria.