The president of the Czech Republic warned that Russia could escalate its war against Ukraine following parliamentary elections in September.

Petr Pavel told The Telegraph in an interview published Thursday that Russian President Vladimir Putin could declare a general military mobilization — a nationwide call-up of reservists and other eligible men for military service — after Russia's parliamentary elections Sept. 20.

He said such a move would be deeply unpopular with voters. The last time Putin ordered a mobilization, many military-age men fled the country to avoid being drafted.

"Russia will have parliamentary elections in September," Pavel said at the NATO summit in Turkey. "President Putin will hardly declare mobilization before, but once the elections are over, then the window will shrink."

Pavel's warning came amid a series of Ukrainian drone strikes that hit Moscow, struck Russian tankers attempting to resupply Crimea with fuel, and set fire to a major oil refinery in western Siberia.

According to The Telegraph, Putin has largely isolated himself as Ukraine's long-range strikes on energy facilities have created mounting domestic problems. Although Kremlin-friendly pollsters still report strong support for Putin, public trust in him has fallen to 69%, its lowest level since Russia invaded Ukraine in February 2022.

Many of the problems have been triggered by Ukraine's drone strikes in and around Moscow and Crimea. Russians are facing long lines at fueling stations, according to The Telegraph. Frustration over the fuel crisis has been running high, with fights breaking out at stations as pumps run dry.

"Russia has a lot of internal problems and challenges at this point," said Pavel, a retired general and former head of NATO's military committee.

"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."

Pavel said allies must use the current pressure on Russia to push Moscow toward peace talks in the coming weeks.

"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," Pavel said.