Juppe, the highest-level French visitor to Australia in 28 years, also condemned continuing divisions within the United Nations Security Council on Syria after objections from Moscow, calling the uncertainty a "scandal".
"We certainly cannot allow the single currency to fall apart because that falling apart would apply also to Europe as a whole," he told reporters in Canberra.
Juppe said eurozone members were unified in their approach, but repeated warnings that Greece must honour commitments made earlier this year in order to win fresh bailout loans.
"Greece has made some mistakes, they have to correct these mistakes and honour the commitments they have made. France and Germany are in full agreement on this issue," he said, speaking through an interpreter.
"In the medium term, we have the means at our disposal to reinforce the euro zone."
Juppe was in Australia for a lightning tour which also took in Russia and New Zealand and is to conclude in China.
Moscow has refused to back Western sanctions against its regional ally and President Dmitry Medvedev has accused some of those protesting against Bashar al-Assad of being "terrorists".
"It's a scandal not to have a clearer position from the UN on such a terrible crisis," said Juppe.
The sensitive issue of the value of China's currency, the yuan, would top his discussions with Chinese officials in the next stage of his tour, Juppe said.
"We believe the yuan is undervalued at present," he added.
China faces growing calls from major trade partners, including the United States and Europe, to let the yuan strengthen at a faster pace.
Critics claim the currency is grossly undervalued, making Chinese exports artificially cheap and giving domestic manufacturers an unfair advantage.
Juppe earlier attended commemorations for the September 11 attacks in the United States at Australia's War Memorial with his local counterpart, Kevin Rudd.
He also met Prime Minister Julia Gillard on issues including Afghanistan and the G20.
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