MOSCOW—The United States said Friday it has laid off nearly 200 local staffers working for its diplomatic missions in Russia ahead of an Aug. 1 deadline set by the Kremlin for their dismissal. The move is just the latest in a series of measures taken by both sides that have strained U.S.-Russia relations. Secretary of State Antony Blinken said the layoffs are regrettable and something the United States had hoped to avert, despite a sharp deterioration in ties between Moscow and Washington, which show few signs of improvement. “These unfortunate measures will severely impact the U.S. mission to Russia’s operations, potentially including the safety of our personnel as well as our ability to engage in diplomacy with the Russian government,” Blinken said in a statement. “Although we regret the actions of the Russian government forcing a reduction in our services and operations, the United States will follow through on our …