Omani Deputy Prime Minister for Cabinet Affairs Fahd bin Mahmoud Al-Said met here today with visiting UK Foreign Secretary William Hague and his accompanying delegation.     Discussions during the meeting dealt with relations and prospects for future cooperation between the two countries and a number of issues and developments at the regional and international arenas . Sultan Qaboos bin Said of Oman met last night with the visiting British Foreign Secretary to discuss ways of strengthening cooperation between the two countries in addition to a number of matters of mutual interest .