European finance chiefs have delayed a decision on the payment of a crucial bailout loan for Greece until October.
The head of the eurozone finance ministers group was speaking at a meeting in Wroclaw, Poland.
The next eight billion euro (£7 billion) instalment of Greece's bailout loan is needed to keep the country from a disastrous debt default.
But officials from the eurozone and the International Monetary Fund (IMF) have delayed their assessment amid questions about whether Greece was doing enough to cut its deficit.
Jean-Claude Juncker said officials welcomed "the renewed, firm commitment of Greece" to its austerity programme and said they "would decide in October on the next tranche".
A delegation from the eurozone, the IMF and the European Central Bank unexpectedly left Athens on September 2, delaying a much-awaited confirmation that Greece was meeting the terms of its 110 billion euro bailout agreed in May 2010.
Fears that Greece might not get the next tranche and default have made Greek bond prices plummet, weighed on the euro's exchange rate with the dollar and caused turmoil on stock markets.