They are expected to demand president Bashar al-Assad allow a ceasefire to allow humanitarian access to the victims of Syria’s repression of anti-government protests.
The group will request that help can be provided for the worst-affected areas.
Prime Minister David Cameron said he hoped the Friends of Syria meeting would find ways to back the opposition and to tighten sanctions.
The UN last night appointed its former secretary-general, Kofi Annan, as a joint envoy with the Arab League on the Syrian crisis.
In an appeal for the world to unite to end the bloodshed, Mr Cameron seized on the death of Sunday Times journalist Marie Colvin as a signal of the regime’s intent. Her killing was not just a tragic loss but “yet another evil act by the Syrian government”, Mr Cameron declared, accusing Mr Assad of murdering children in the crackdown.
“We do need to work hard to work out what more we can do as an international community,” he said, appealing to Moscow and Beijing.
“It’s absolutely vital that the international community comes together, does this work, sends this message, and I hope that the foreign ministers’ meeting in Tunis will back that up as strongly as they can.” Mr Hague said the UK was “determined to pursue every possible peaceful means of pressurising Assad’s regime until it ceases its brutal repression of the Syrian people.
“The Friends of Syria group is an essential means of doing that. The meeting will show the strength of support for the Arab League’s efforts to resolve the crisis.
“The UK looks forward to working closely with Arab and international partners to end the violence and begin the process of transition that the Syrian people deserve.”
US secretary of state Hillary Clinton said she was certain the Syrian regime would fall and that getting aid in was a priority.
“Our immediate focus is on increasing the pressure.
“We have got to find ways of getting food, medicine and other humanitarian assistance into those affected by violence. This takes time and it takes diplomacy.”