Turkish President Recep Tayyip Erdogan has held a phone conversation with his Russian counterpart, President Vladimir Putin, in which he called for a 30-kilometre (19-mile) security corridor at the Turkish border with Syria, according to his office.The call came three weeks after Turkey launched air and artillery strikes in Syria and Iraq following an explosion in Istanbul on November 13 that killed six people and wounded dozens of others.Turkey, meanwhile, has acted as a mediator with the United Nations on an agreement that guarantees grain exports from both war-hit Ukraine and Russia, two of the world’s biggest producers.In the call, Erdogan said Ankara and Moscow could start work on exporting other food products and commodities through the Black Sea grain corridor, it added, without providing further details.Russia has urged the UN to push Western countries to lift some sanctions imposed on it after it invaded Ukraine in February."