WASHINGTON (Reuters) - The United States said on Friday it would convene a meeting of Iraqis in the southern city of Nassiriya on Tuesday to discuss the future of Iraq (news - web sites) and an eventual interim authority to govern the country. The meeting, which a U.S. official said was to be chaired by U.S. presidential envoy Zalmay Khalilzad, was expected to be the first in a series Washington aims to organize leading to a Baghdad conference to choose an Iraqi governing authority. It was expected to include Iraqis from inside and outside the country, including opposition figures and...