"We have no intention of supplying lethal weapons at this time," Defence Minister Jean-Yves Le Drian said Wednesday.
"Russia's position with respect to its support for the Ukrainian separatists is not acceptable, we say it firmly, and we are continuing sanctions as a result," said Le Drian in Paris, following talks with his Canadian counterpart Rob Nicholson.
"At the same time, we must avoid by all means the continuation of this worsening conflict."
The minister responding to a mounting debate triggered by news that the United States is considering arming the Ukrainian government.
Washington is once again mulling military support to Ukraine after fierce offensives by Kremlin-backed rebels, but experts fear it will only justify Russian conspiracy theories and drive East
and West closer to full-blown war.
The recent rebel attacks across key parts of the frontline in eastern Ukraine may have been timed precisely out of fear the United States could soon get involved.
"One reason the rebels have intensified their offensive now is to make gains before potential US arms arrive," said Andrew Wilson, author of "Ukraine Crisis: What it means for the West."
"The US faces a moral dilemma: if it does not act now, the conflict could worsen. But there are big risks to getting involved."
The White House is once again under pressure to up its involvement in the 10-month-old Ukraine conflict as ceasefire talks collapse and casualties soar.
The UN says 278 people were killed in the 12 days to January 21 alone as Russian-backed rebels sought to capture key transport and communication hubs.
An independent report released Monday by eight former senior American officials said it was time for Washington to provide $3 billion (€2.7 billion) in military assistance to Ukraine.
"The West needs to bolster deterrence in Ukraine by raising the risks and costs to Russia of any renewed major offensive," the report said.
French President Francois Hollande, German Chancellor Angela Merkel and Ukrainian President Petro Poroshenko called on Sunday for "an immediate ceasefire" in eastern Ukraine, the French presidency said, a day after the latest truce talks collapsed.
Speaking by phone to discuss a surge in deadly fighting between Ukrainian troops and pro-Russian rebels, the three leaders also expressed their regret for "the failure of the talks" in Minsk on Saturday, the Elysee palace said.