France has already done its bit by "reducing its public spending and reforming its economy", Le Maire told Germany's Die Zeit weekly. "We expect Germany to join the movement, by adopting more aggressive wage policies and investing more."
With five days of exploratory coalition talks set to end on Thursday evening, the centre-left SPD is demanding more public spending but Merkel's conservatives want to keep the country's budget balanced, arguing that they are saving for the ageing population's future.
"Germany has already taken decisions in the right direction, a minimum wage was introduced," Le Maire said, a barbed comment since the move was taken at the SPD's initiative under the previous government.
And he called for " investment in big projects, in innovation, research and infrastructure".
Germany is expected to announce on Friday a budget surplus for 2017 that surpasses 10 billion euros, German media reported.
That would put more pressure on Merkel for greater wealth redistribution.
The German engineering workers' union IG Metall this week launched a series of strikes for six percent wage rises.
"The sooner we have a solid government in Germany, the better for France," Le Maire commented.
The SPD supports President Emmanuel Macron's plans for European Union reform, while Merkel's Christian Democrats are more reserved on the idea.