Western and Arab governments have pledged more political and material support for the civilian Syrian opposition.

There was also a call for an immediate halt to arms supplies to the Assad government.

US Secretary of State John Kerry said Washington would aid Syrian rebel fighters with food rations and medical supplies.

He said the US plans to “more than double” aid to the opposition Syrian National Coalition, providing an additional $60m.

A final statement after a meeting of the "Friends of Syria" diplomatic group in Rome added: "The regime must immediately stop the indiscriminate bombardment against populated areas which are crimes against humanity and cannot remain unpunished".

It added: "The ministers pledged more political and material support to the (Syrian National) coalition as the sole legitimate representative of the Syrian people and to get more concrete assistance (into) Syria."

They gave no detail of what kind of support would be supplied.