US 'could hit Syria again if it keeps on gassing its people'
Theresa May and Donald Trump have agreed a "window of opportunity now exists" to persuade Russia that its links with Bashar Assad's regime are no longer in its strategic interest as they discussed the situation in Syria.
The two leaders spoke about the crisis by telephone as the US president thanked the PM for her backing of his military strikes against Syrian government forces last week.
A Downing Street spokesman said: "The Prime Minister and the President agreed that a window of opportunity now exists in which to persuade Russia that its alliance with Assad is no longer in its strategic interest.
"They agreed that US Secretary of State (Rex) Tillerson's visit to Moscow this week provides an opportunity to make progress towards a solution which will deliver a lasting political settlement."
The Prime Minister, who is on a short walking holiday in Wales, is being kept up-to-date on events in Syria.
Mr Trump ordered a series of missile strikes last week in response to the deaths of more than 80 people, including children, during a chemical attack in a rebel-held town.
The US president's spokesman Sean Spicer warned that further action would be considered in certain circumstances.
"When you watch babies and children being gassed, and suffer under barrel bombs, you are instantaneously moved to action. I think this President has made it very clear that if those actions were to continue, further action will definitely be considered by the United States."
The move came as Foreign Secretary Boris Johnson warned that senior Russian military officers involved in co-ordinating President Assad's campaign of repression against his own people could face international sanctions.
At a meeting of G7 foreign ministers in Lucca, Italy, Mr Johnson issued a fresh appeal for Russian President Vladimir Putin to abandon his backing for his Syrian ally following last week's chemical weapons attack.
He said if the Russians continued to support the regime in Damascus, they would be "contaminated" by its actions and could find themselves the target of new international sanctions.
"We will be discussing the possibility of further sanctions certainly on some of the Syrian military figures and indeed on some of the Russian military figures who have been involved in co-ordinating the Syrian military efforts and are thereby contaminated by the appalling behaviour of the Assad regime," Mr Johnson told reporters.
Mr Johnson also defended his decision to pull out of talks with his Russian counterpart Sergey Lavrov, saying it was important Mr Tillerson had the "clearest possible mandate" when he went to Moscow to deliver the response of the G7.