Greece's euro zone partners are not discussing the prospect of the country leaving the currency union and might offer concessions to Athens' original bailout program, Portugal's finance minister said on Tuesday.

Wide differences over pension and labor reforms remained between Greece's government and its international creditors, although negotiations have made progress in other areas as the country's cash position becomes increasingly critical.

Yet Portugal's Maria Luis Albuquerque, one of the euro zone finance ministers who form the Eurogroup, said a Greek exit was not being discussed.

"Our central scenario is that Greece continues to stay in the euro zone ... because it is what the Greek people want," Albuquerque said at an event in London. "We are not discussing any other alternative, even though such a scenario would be worrying for everyone."

Portugal ended its own 2011 bailout from the European Union and the International Monetary Fund in May last year.

While highlighting the importance of fiscal discipline and structural reforms, Albuquerque said there may be some room to amend the terms of Greece's original bailout.

"Greece had probably deeper rooted problems (than Portugal) and needs maybe adjustments to what was the initial design of the (bailout) program, but it needs to want to do it," Albuquerque said.

Talks on an interim deal between a reshuffled Greek negotiating team and representatives of the European Commission, the European Central Bank and the IMF have been under way since last Thursday.

The aim is to achieve a technical-level accord that would enable euro zone finance ministers to declare when they meet on May 11 that there is a prospect of concluding Greece's bailout review successfully.

"Next Monday is not a key date ... The Eurogroup can reconvene at any time," Albuquerque said.