The United Nations said Friday it will host separate talks with rival sides in Syria from May 4 in a bid to start negotiations to end the four-year conflict. "The Geneva consultation invitations have gone out a couple of days ago," U.N. spokesman Ahmad Fawzi told reporters, saying the talks would last between four and six weeks and would be at "mostly ambassadorial level and expert level." In January, the U.N. peace envoy for Syria, Staffan de Mistura, said conditions were not yet right to try to launch more talks after the first two rounds of negotiations in Switzerland failed.