Russia is in effect stopping humanitarian aid getting to civilians in besieged areas of Aleppo in Syria because it will not agree to a ceasefire to allow its safe passage, Downing Street has said.
As the United Nations Security Council met in New York, Theresa May's official spokeswoman condemned the Syrian regime "and their influencers" for preventing aid getting into rebel-held areas of Aleppo.
It came after Russian ambassador to the UN Vitaly Churkin said a proposed Security Council resolution calling for a 10-day pause in hostilities to allow in aid had been overtaken by events.
He said Syrian and Russian forces, which have been bombarding east Aleppo, have now retaken a vital road so it can be "freely used for humanitarian supplies".
But asked if the Government was considering air drops, Mrs May's spokeswoman told a Westminster briefing: "It would be possible to get aid in via road to Aleppo, we've seen humanitarian convoys do it in the past, it should be possible.
"The only reason it is not is because the Syrian regime and their influencers are preventing it."
Asked what she meant by influencers, the spokeswoman said: "Be it Russia, or others."
She went on: "They are one of the people that are backing the regime."
Asked if she meant Russia was directly stopping aid getting in, the spokeswoman said: "Two points.
"One, they, in a sense that the Syrian regime backed by Russia are not agreeing to a halt or a cessation of hostilities so that you can get aid in, so by that they are stopping it.
"Two, if you look at the actions they have taken at the UN Security Council, they vetoed a resolution that called for aid to be brought into Aleppo and to end the bombardment of Aleppo."
Britain and France are also seeking a Security Council resolution aimed at ensuring that members of president Bashar Assad's Syrian regime who are involved in using chemical weapons are punished.
Earlier at Prime Minister's Questions, Mrs May said: "I think the Security Council debate is very important and there is an important message to send to Russia that they actually use their influence with the Assad regime to stop these appalling atrocities in Aleppo and let humanitarian aid through."