Ukraine has two months to restart peace talks or risk Russia escalating the war, the Czech president has said.
Petr Pavel warned that Vladimir Putin could declare a general mobilisation after elections set to be held on Sept 20.
“I believe that the window is there for us to keep pushing and giving Russia a clear message that we are willing to start negotiations,” the retired general and former head of Nato’s military committee told The Telegraph.
He added: “Russia will have parliamentary elections in September. President Putin will hardly declare mobilisation before, but once the elections are over, then the window will shrink.”
Mobilisation would probably be deeply unpopular with voters.
Mr Pavel said allies must use current pressure on Russia to force peace talks in the coming weeks.
“Russia has a lot of internal problems and challenges at this point,” he said at the Nato summit.
“The Russian public is turning increasingly against the war. President Putin will have difficulties keeping calm at home, and if this pressure continues, if Ukraine continues to be capable and successful in hitting targets deep in Russian territory, it will create conditions where Russia will be more inclined to negotiate.”
In the past month alone, Ukraine’s drones have struck Moscow, hit Russian tankers attempting to resupply Crimea with fuel and set fire to a major oil refinery in western Siberia.