West must stop 'pulverisation' of Aleppo - Boris Johnson
Foreign Secretary Boris Johnson has said the West must consider new military options against Syrian forces to stop Aleppo being "pulverised".
The rebel-held east of the city is under renewed bombardment after a ceasefire deal broke down.
Mr Johnson said a new set of "kinetic" options would be considered at a UK meeting of foreign ministers on Sunday.
Many people had changed their minds since 2013, when MPs blocked military action against Assad's forces, he said.
Mr Johnson has summoned a meeting of foreign ministers, including US Secretary of State John Kerry, as well as ministers from France and Germany on Sunday, to consider a new way forward in Syria and Iraq.
He told the foreign affairs committee: "Most people - I think including John Kerry - feel that the process of discussion with the Russians has basically run out of road. On Sunday, we will be talking about all the options that we think are available to us and to the West.
"I am not going to pretend that there is any easy answer here, because there isn't. Most people, I think, are now changing their minds about this and they are thinking 'We can't let this go on for ever, we can't just see Aleppo pulverised in this way, we have to do something'.
"Whether that means we can get a coalition together now for more kinetic action now, I cannot prophesy, but certainly what most people want to see is a new set of options."
Aleppo, once Syria's largest city and the country's commercial and industrial hub, has been divided roughly in two since 2012, with President Assad's forces controlling the west and rebel factions the east.
'Run out of road'
UK MPs have urged the government to consider establishing a no-fly zone over Aleppo, which would involve western powers being prepared to destroy Russian and Syrian government planes and air defences.
Some MPs are pushing for a no-bombing zone instead, which could involve targeting runways and munitions stores and potentially using naval ships to launch missile attacks on helicopters dropping barrel bombs.
Mr Johnson said: "It is right now that we should be looking again at the more kinetic options, the military options, but, you know, we must be realistic about how these, in fact, work and what is deliverable.
"And certainly, you can't do anything without a coalition, without doing it with the Americans, and we're still a pretty long day's march from getting there, but that doesn't mean that discussions aren't going on, because they certainly are."
He said: "It is vital we do not raise false hopes. We know the difficulties and implications of a no-fly zone or no-bombing zone, no matter how easy these concepts may be made to seem."
Earlier this week Mr Johnson called for demonstrations outside the Russian embassy in London, arguing that "all the available evidence" pointed to its responsibility for the bombing of an aid convoy in Syria. Moscow accused him of "Russophobic hysteria".