Afghanistan-no link-break-of-gauge 1,520 mm (4 ft 11 27⁄32 in)-railway link to Afghanistan is being built using 1,435 mm (4 ft 8 1⁄2 in)standard gauge. Armenia-no link-break-of-gauge 1,520 mm (4 ft 11 27⁄32 in). Azerbaijan-open-break-of-gauge 1,520 mm (4 ft 11 27⁄32 in)-only via the Azerbaijani exclave Nakhchivan,railway link to Azerbaijan proper is being built.