The United States and France have accused Syrian regime leader Bashar al Assad on Thursday of scuppering talks to end the Syrian civil war.
The talks were suspended hours before donors were due to meet on Thursday to raise aid for Syria.
French Foreign Minister Laurent Fabius said that Damascus and Moscow are “torpedoing the peace efforts” by hitting places near Aleppo, and said world powers would hold "in-depth consultations" on their actions at the conference.
The United Nations announced that it paused fruitless peace talks on Wednesday as the Syrian regime said that it had cut the key supply route to Syria’s second city Aleppo from the Turkish border with the help of Russian air strikes.
Moscow is backing the regime and Russian Foreign Minister Sergei Lavrov said on Wednesday they are not going to stop until the “terrorists” are defeated.
US Secretary of State John Kerry said that the regime proved that it was not serious about the talks.
"The continued assault by Syrian regime forces -enabled by Russian air strikes- against opposition-held areas... have clearly signalled the intention to seek a military solution rather than enable a political one," he said.
British Foreign Minister Philip Hammond accused Russia on Wednesday of conducting air strikes that are targeting Syrian opposition forces instead of fighting DAESH.
He said that Russia’s main aim is to set an Alawite mini-state in Syria for its ally regime leader Bashar al Assad.
Humanitarian crisis is getting bigger
The suspension of the talks came before the donors meeting that aimed to raise $9 billion in aid for Syria and neighbours to cope with millions of refugees in their countries.
The United Kingdom pledged $1.74 billion in aid to be spent between 2016 and 2020.
The UK Prime Minister David Cameron described the situation as “the world’s biggest humanitarian crisis.”
Some 4.6 million Syrians have fled to nearby countries -Jordan, Lebanon, Turkey, Iraq and Egypt- while hundreds of thousands have journeyed to Europe in the region's biggest migration crisis since World War II.
"With hundreds of thousands of people risking their lives crossing the Aegean or the Balkans, now is the time to take a new approach to the humanitarian disaster in Syria," Cameron said.
Norwegian Foreign Minister Borge Brende said there was a "moral imperative, human imperative" to act.
"It's a lost generation if we're not successful tomorrow," he said ahead of the conference.
UN-mediated talks to end the war in Syria are on pause until February 25, UN Envoy Staffan de Mistura said on Wednesday.
Mistura also said that the talks had not failed but needed immediate help from international backers led by the United States and Russia.
On the other hand Riad Hijab, High Negotiations Committee (HNC) chief coordinator, said late Wednesday the group "will not return until the humanitarian demands are met or (we) see something on the ground."