LAS VEGAS (AP) — Government leaders in the United States and Mexico are close to signing a pact to add areas south of the border to Colorado River water sharing agreements involving seven Western U.S. states, officials said Friday. U.S. Bureau of Reclamation officials characterized the talks as delicate while final documents circulate among 15 water agencies and state officials in Arizona, California, Colorado, Nevada, New Mexico, Utah and Wyoming. “The concern is that these are sensitive negotiations,” said Kip White, a bureau spokesman in Washington, D.C. “It has taken a long time to get here. We’re looking forward to …