Syria 'chemical attack': UK, US and France agree action
Prime Minister Theresa May has agreed with her US and French counterparts that the international community needs to respond to an alleged chemical attack in Syria.
In phone calls, Emmanuel Macron and Donald Trump said those responsible should be "held to account".
The international chemical weapons body has sent a team to the site in Douma.
But Russia, which provides military support to Syria, has said there is no evidence of a chemical attack.
Medical sources say dozens of people were killed, including children, during the alleged toxic bombing of formerly rebel-held Douma, in the Eastern Ghouta region.
It comes ahead of a UN vote on a draft resolution from the US to begin a new inquiry to establish who is to blame.
- Syria 'chemical attack': What we know
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- Russia: No evidence of chemical attack
Earlier, US President Trump cancelled a planned trip to Latin America to focus on the issue. He has pledged a "forceful response".
Downing Street said the separate phone calls established the countries would work together to take action to "uphold the worldwide prohibition on the use of chemical weapons".
A spokeswoman added: "They agreed that reports of a chemical weapons attack in Syria were utterly reprehensible and if confirmed, represented further evidence of the Assad regime's appalling cruelty against its own people and total disregard for its legal obligations not to use these weapons."
It is not clear what support the UK will offer in response, but BBC deputy political editor John Pienaar says refuelling aircraft is a probable option.
He added any direct action would require parliamentary consent.
The White House said Mrs May and Mr Trump both condemned Mr Assad's "vicious disregard for human life" and agreed the use of chemical weapons should not continue.
Last year, President Trump ordered a missile strike in retaliation for a Sarin gas attack against a Syrian town.