French President Francois Hollande and German Chancellor Angela Merkel on Saturday held "constructive and fruitful" phone talks on the crisis in Greece and the eurozone, Hollande's office said.

They exchanged "views on the situation in Greece, the preparations for a G20 summit and the next European Council meeting on June 28 and 29," a statement said.

The talks come on the eve of the Greek elections, deemed crucial for the future of the eurozone, and follow a tense week between Paris and Berlin, as France's new Socialist government tries to find common ground with Merkel, a centre-right, pro-austerity champion.

On Thursday, Merkel irritated some partners by calling proposed solutions to the crisis quick fixes smacking of "mediocrity" that failed to address core problems.

French Prime Minister Jean-Marc Ayrault responded by urging Merkel to avoid "simplistic talk".

Ayrault seemed to smooth things over Friday, saying Berlin and Paris should work "hand-in-hand for a solution to pull Europe out of crisis", and calling for stronger contacts with Berlin.

"Without growth, even if you move to reduce debt, you won't be all right," Ayrault said.

He added it was necessary to find "strong initiatives for growth and to develop effective financial stability mechanisms."

A strong Franco-German partnership has been considered key to progress and problem-solving in the 17-nation eurozone, and the wider European Union, in the past.