Hanoi on Sunday ruled out the possibility of any formal agreement with Washington on its request for access to a Russian naval base on Vietnam's central coast after Moscow's lease expires in 2004. "Vietnam won't sign an agreement with any country on using Cam Ranh port for military purposes," foreign ministry spokeswoman Phan Thuy Thanh told the official Vietnam News Agency. But the ministry spokeswoman left open the possibility of US access to the base on an informal or multilateral basis. Vietnam has allowed port calls at Haiphong and Ho Chi Minh City by warships from a host of foreign ...