The German chancellor and French president will seek to align their positions on Greece's economic woes before they hold separate meetings with Greek Prime Minister Antonis Samaras later this week.
Merkel and Hollande have both pointed to a progress report due next month by Greece's international auditors on its efforts so far to get its recession-hit economy moving again before making any decisions.
But the German leader, who has again topped the Forbes list of the world's most powerful women, has insisted Greece stick to what it signed up to and says Europe's credibility is at stake.
She will receive Samaras on Friday before he meets Hollande in Paris on Saturday.
"I go into the talks this week aware that we must ensure that every partner fulfills their obligations -- that Germany, France and all the other countries fulfil their obligations," Merkel said on a visit to Moldova Wednesday.
"What Europe needs is credibility in all political questions," Merkel added.
German Finance Minister Wolfgang Schaeuble hammered home that message on Thursday, telling SWR public radio: "More time is not a solution to the problems."
"More time would, in case of doubt, mean more money," he said.
After meeting Samaras Wednesday, Eurogroup chief Jean-Claude Juncker said Greece's place was in the eurozone but urged its government to redouble reform efforts to secure continued EU-IMF financial aid, warning it was Greece's "last chance."
Samaras told the German daily Bild Wednesday that Greece needed "a little breathing space" to make spending cuts and reforms that are a condition for the next tranche of a €130-billion ($161-billion) bailout
In return for the €31.5 billion installment, Athens has committed to €11.5 billion of spending cuts for 2013 and 2014, a period that Samaras wants to extend by two years.
"As regards the lengthening of the adjustment period, it will depend on the findings of the troika mission," Juncker said referring to auditors from the European Commission, European Central Bank and International Monetary Fund.
In another German newspaper Thursday, the Greek leader pledged his country would repay the aid it has received to keep it afloat and fulfil its commitments.
And in French daily Le Monde, he also warned Greece's exit from the euro would start a devastating domino effect that would hit other members of the common currency.
Europe is experiencing one of its worst crises, Merkel said in a video message on Thursday.
"This crisis has built up over many years and will therefore take a long time to overcome. It will be difficult," she said.
"But I am deeply convinced that at the end of this path, we will have a sustainable and strengthened eurozone and European Union."
The foreign ministers of Germany and the three Baltic states have jointly warned the debt crisis risks splitting Europe between north and south in an echo of the Cold War division.
The chancellor, entering the countdown to elections by October 2013, faces resistance at home to granting Greece more aid after nearly three years of the eurozone lurching from one crisis to another.
But at the helm of Europe's effective paymaster, she has been under pressure to chart decisive action to shake off the debt crisis, inspire confidence in the markets and keep the bloc intact.
"It is about Europe as a whole this week, this is the spirit that guides me in my talks with the French president," Merkel said on Wednesday.
Her relations with the new French president got off to a strained start as Merkel's insistence on austerity to fight the crisis was at odds with Hollande's emphasis on favouring growth measures.
They are due to give statements without taking questions at around 1700 GMT before a working dinner, where they were also expected to discuss the crisis in Syria.