VILNIUS—Russia would only consider releasing Kremlin critic Alexei Navalny if its leadership was hit with painful personal sanctions, a close ally said ahead of a meeting with European policymakers in Brussels on Sunday. European foreign ministers are expected to agree on Monday to impose sanctions on allies of Russian President Vladimir Putin in response to the jailing of Navalny. Navalny was arrested last month on his return from Germany following treatment for poisoning with what many Western countries say was a nerve agent. He was jailed on Feb. 2 for violating parole on what he and the Western countries said were trumped-up charges. He lost an appeal on Saturday. Leonid Volkov, Navalny’s chief of staff, told Reuters on Saturday he believes Putin would only consider releasing him if hit by sanctions. “Putin is a dictator, but he is quite rational. If the upsides of having Navalny in prison become less …