(Recasts with presidency on planned meeting)
PARIS, March 12 (Reuters) - France threatened on Wednesday to pull out of planned ministerial talks with Russia next week unless Moscow helps to reduce tension between Russia and Ukraine.
The meeting is a regular fixture of bilateral relations between Russia and France but happens to be scheduled this year for March 18, two days after Ukraine's Crimea region holds a referendum on joining Russia.
After French President Francois Hollande and his Russian counterpart Vladimir Putin spoke by phone earlier, the Kremlin said Russia and France would continue talks on Ukraine during the visit by the French foreign and defence ministers.
However, France put the caveat on its attendance.
"This meeting can be held depending on progress over Ukraine ... if on the Russian side there are elements that allow us to think this meeting will be useful," an official at Hollande's office said.
In an earlier statement, Hollande's office said he had told Putin he had to do everything to stop Crimea, now controlled by Russian forces, from joining Russia, something that would be an "unacceptable annexation".
"The president reminded (him) that the March 16 referendum, for which preparations are ongoing in an opaque way, has no legal basis," Hollande's office said.
"The president underlined that there was still time to avoid a pointless and dangerous escalation."
The tone in the Kremlin's statement differed, saying Putin and Hollande had discussed "possibilities for stepping up international support" for a solution to the crisis in Ukraine. (Reporting by Elizabeth Pineau and John Irish; Writing by Leigh Thomas; Editing by Alison Williams)