But European and Gulf states, angered by Russia's military intervention that tilted the war in favour of President Bashar al-Assad, will only contribute if Moscowsecures a peace settlement that sets the terms for an eventual political transition, western diplomats say.
"They [Russia] go in, they mess it all up, they break everything and want everyone to pay for it," said a European diplomat.
The issue is expected to be raised at UN-backed talks between the Syrian government and rebels that begin in Geneva on Thursday. Russia is the dominant foreign player involved in the war, but after helping broker a ceasefire between the warring parties in December, it has struggled to bring the adversaries closer to a political agreement.
Mikhail Bogdanov, Russia's deputy foreign minister in charge of Middle East issues, told a meeting of EU ambassadors in Moscow last week that the reconstruction of Syria would top the agenda very soon, according to European diplomats. He said "tens of billions of dollars" would be needed, while warning that "nothing" should be expected from Russia, the diplomats said.
"The Russians really do not want to inherit a completely destroyed Syria — that's a problem that would stick with them as long as Iraq has been haunting the Americans," said a Middle East-based diplomat.But the Russian initiative could face resistance — particularly as Russian air strikes were responsible for destruction in cities such as Aleppo. The conflict has reduced entire neighbourhoods across the country to rubble and forced millions of people from their homes.
But the Russian initiative could face resistance — particularly as Russian air strikes were responsible for destruction in cities such as Aleppo. The conflict has reduced entire neighbourhoods across the country to rubble and forced millions of people from their homes.
EU member states have differed on whether to insist on Mr Assad's departure as an explicit condition for a settlement or back a transitional arrangement. Countries including the UK, France and the Netherlands believe the war will not end until he goes, but others argue that should not stop efforts to ease the violence.
Federica Mogherini, the EU's foreign policy chief, plans to host an international conference on Syria's future in April.
"Mogherini would like to use that to put the EU in the forefront of shaping the debate on reconstruction. The UK and France are very cautious about rushing into something that isn't going to hold and inadvertently propping up Assad," said another European diplomat.
The Geneva negotiations follow negotiations in Kazakhstan mediated by Russia and Turkey, which supports the Syrian opposition.
Russia used those talks to table a draft of a new Syrian constitution, despite the fact that work on a charter was originally part of the agenda for the Geneva process. The second round of talks in Astana wrapped up without visible progress last week and Moscow is expected to raise its draft charter in Geneva.
Details of Russia's draft constitution have not been made public, but a crucial issue is how long Mr Assad would be able to cling to power. Rebels and diplomats say the draft peddled by Russia would involve a devolution of powers, with portfolios, such as the interior, defence and foreign ministries, gaining extra power.
Some opposition figures are slowly warming to the idea, which would essentially put in place an Iraq or Lebanon-style power-sharing system.
"It is far from ideal and not something we had aspired to, but I think it is better than war," one opposition figure said.
However, others argued it is a charade the opposition should steer clear of.
"It doesn't matter much if you have a new and powerful post but you don't have the intelligence forces or military behind you," said an opposition figure.
Russian Middle East experts blame the Syrian government and Iran, another backer of Mr Assad, for being the biggest obstacles to a political settlement.
The Kremlin believes that neither that problem nor convincing European powers to support a Russian-brokered political deal can be solved without clarity over US policy in Syria. The Obama administration, which was criticised by Syria's opposition for not doing more to end the violence, was increasingly marginalised as Russia's influence grew.
US President Donald Trump has suggested his priority in Syria will be fighting Isis and not pushing for Mr Assad to step down. But his administration has increased the pressure on Iran, the main regional backer of the Syrian regime.
"The Trump administration's hard line on Iran could be very useful in getting Iran to make concessions," said a former Russian diplomat. "But for that we need a clear message from Washington."