A defiant Alexei Navalny was sentenced Monday to 15 days in jail for resisting arrest and fined 20,000 rubles (about $350) for organizing Russia’s nationwide anti-government protests over the weekend. With a selfie posted to Twitter from a Moscow court, the Russian opposition leader sent a tweet reading, “The time will come when we will put them on trial.” In the courtroom, he called on Russian Prime Minister Dmitri Medvedev to appear and explain why the protests took place—his activist group has accused Medvedev of corruption and illegally amassing vast real-estate holdings. Navalny has previously declared that he intends to run for president against Vladimir Putin next year. The Kremlin on Monday accused demonstrators of “provoking violence” and organizers of “consciously misleading people” with protests that included tens of thousands of people across Russia. Kremlin spokesman Dmitry Peskov told reporters Monday that while Putin respects the right to peacefully assemble, his government regarded Sunday’s protests as unlawful. More than 1,000 people were detained, according to The Guardian. In a statement late Sunday, the U.S. State Department said it condemned the detention of the hundreds of peaceful protesters.