Senior officials from Iran, Russia and Turkey will meet in Geneva on June 18-19 for consultations with the United Nations about setting up a constitutional committee for Syria, UN Syria envoy Staffan de Mistura said in a statement on Wednesday. He will invite other countries for relevant discussions in due course, the statement said. De Mistura is tasked with choosing the members of the committee, which is expected to rewrite the Syrian constitution, paving the way for new elections as part of a post-war political reform. The UN envoy recently embarked on a regional tour that covered Turkey, Iran and Egypt.