The European Commission will send "in the next few days" a team of experts to Athens tasked with concluding work on a new rescue package for debt-ridden Greece by the end of the month.
The Commission's comments came after Greece announced new budget cuts to reduce its public deficit.
In his annual speech on the country's economy, Greek Prime Minister George Papandreou vowed to press ahead with the deep spending cuts demanded by its international creditors.
Mr Papandreou said: "At the point where the eurozone is ... every delay, every hesitation, every option other than strict compliance with our commitments ... is dangerous for the country and its citizens.''
Public anger over cuts boiled over into clashes between police and protesters and more than 100 people were detained.
At least 20,000 people joined the protests in Thessaloniki.
A huge banner displayed by marchers read: "We owe nothing, we pay nothing, we sell nothing, we fear nothing.''
Eurozone leaders announced a second rescue package, worth €159bn, for debt-ridden Greece in July, but many Greeks fear the stringent conditions set for the money to trickle down will only make unemployment worse.
However, French Foreign Minister Alain Juppe has said Greece must honour all of its commitments in order to secure the second eurozone bailout.
"Greece has made some mistakes. They have to correct these mistakes. They also have to honour the commitments that they have made," he told reporters on a visit to Australia.
