On Thursday, Defense Secretary Jim Mattis urged caution on attacking Syria.
The same officials say Syria has continued to produce or procure chlorine, which also has industrial and agricultural uses.
The United States is consulting with Britain and France about a joint military response to an alleged toxic gas attack in Douma that medics and rescuers said left at least 40 people dead on Saturday.
May spoke with President Trump on Thursday night about the worldwide response to Syria, and they "agreed that the Assad regime had established a pattern of unsafe behaviour in relation to the use of chemical weapons", according to the Downing Street.
"We have not yet made any decision to launch military attacks into Syria", Mattis told lawmakers on the House Armed Services committee.
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President Donald Trump this week signed a law making it easier to prosecute website operators in the future. The Texas Attorney General's office said Backpage.com has pleaded guilty to human trafficking in Texas.
Meanwhile, Russia has called for a UN Security Council meeting on Syria on Friday. Initial reports indicated the use of chlorine gas, possibly in addition to the nerve agent Sarin.
"Japan can not make a judgment on whether Assad's government forces really used chemical weapons", a senior Foreign Ministry official said of the latest attack.
Trump is slated to speak with French President Emmanuel Macron and British Prime Minister Theresa May Thursday evening. Trump's ambassador to the United Nations, Nikki Haley, told NBC News on Thursday the administration has "enough proof" of the chemical attack but is still considering its response.
Opposition Labour leader Jeremy Corbyn said it is "vital that parliament has the chance to debate and decide in advance" of any military action, which he warned "risks a risky escalation of the conflict".
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".
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Congress leader Selja also charged the prime minister with doing politics over the legacy of the Dalit icon. Unnao ganrape involves BJP MLA Kuldeep Singh Sengar and few of his close aides.
French President Emmanuel Macron claimed that the country had "proof" the Assad regime used chemical weapons in Douma and would support any USA action.
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".
The U.S. stance on striking Syria is no clearer, even after President Trump tweeted that missiles "will be coming". "We need to know where that's going, what the objective of it is before we take that act".
Earlier on Thursday, Syrian President Bashar al-Assad warned the West against attacking Syria, saying accusations about the suspected chemical attack on Douma were "fabricated".
Trump posted a tweet on Wednesday warning Russian Federation to "get ready" because missiles "will be coming" to Syria. Russia's ambassador to Lebanon said any missiles fired at Syria would be shot down and the launching sites targeted - a stark warning of a potential major confrontation.
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She added that she was anxious about the "appearance of fairness", given the stakes. According to the filing, Cohen is " under criminal investigation ", with the U.S.