By Elizabeth Piper MOSCOW (Reuters) – Russia signalled on Monday it might ban Western airlines from flying over its territory as part of an “asymmetrical” response to new European Union sanctions over the Ukraine crisis. Blaming the West for damaging the Russian economy by triggering “stupid” sanctions, Prime Minister Dmitry Medvedev said Moscow would press on with measures to reduce reliance on imports, starting with increasing output of domestic aircraft. Medvedev suggested Russia should have hit back harder over the action by the United States and European Union to punish Moscow for its role in Ukraine, saying it had been too patient in the worst confrontation with the West since the Cold War. “If there are sanctions related to the energy sector, or further restrictions on Russia’s financial sector, we will have to respond asymmetrically,” he told Russian daily Vedomosti, adding the airlines of “friendly countries” were allowed to fly over Russia.