French Defence Minister Jean-Yves Le Drian, speaking on French television, said he feared a "dramatic spiral" in violence if dialogue with Moscow did not succeed.
Mr Hammond dismissed an earlier claim from France’s Mr Hollande that current talks were the “last chance for peace” in Ukraine – noting that a military conflict is already under way. But he agreed that a political solution was the only way to end the crisis, adding that “the Kremlin, Mr Putin, has to understand he will pay a political and economic price for what he is doing in the Ukraine”.
At least 5,000 people have been killed in eastern Ukraine since April 2014, when the country's Russian-backed president Viktor Yanukovich was forced out during mass street protests in Kiev.