Greek Prime Minister George Papandreou has asked for the activation of an aid package from the European Union and International Monetary Fund aimed at pulling the eurozone member out of a debt crisis.
'It is a national and imperative need to officially ask our partners in the EU for the activation of the support mechanism we jointly created,' Mr Papandreou said in statements broadcast live.
Greece is negotiating the terms of a €40bn to €45bn package with EU and IMF officials.
Athens has been under pressure after Greek bond yields hit 12-year highs yesterday and imperilled the country's efforts to cut its €300bn debt load.
Mr Papandreou said markets did not give Greece the time it needed to turn its economy around and spiralling lending rates were threatening to negate the effect of painful austerity measures.
He said: 'We will not allow it. Our partners will decisively contribute to provide Greece the safe harbour that will allow us to rebuild our ship.'
Mr Papandreou said the EU would send markets a strong message that it can protect common interests and the common currency.
Ireland has committed about €450m to the aid package.
Aid package available 'within days'
Greek Finance Minister George Papaconstantinou has said the aid should be available within a few days.
Mr Papaconstantinou said Greece faced no immediate problems in financing even though it has to raise about €9bn by the end of May to cover its obligations.
IMF head Dominique Strauss-Kahn said the IMF would act swiftly on Greece's call for help.
Mr Strauss-Kahn said: 'We are prepared to move expeditiously on this request.
'We have been working closely with the Greek authorities for some weeks on technical assistance, and have had a mission on the ground in Athens for a few days working with the authorities and the European Union.'
German Chancellor Angela Merkel said Greece must forward a credible savings programme before eurozone nations provide aid.
Ms Merkel said: 'Greece must play its part in ensuring that Greece's finances return to a solid path.
'The stability of our currency is the first priority ... and the savings plans absolutely have to be credible.'
