Visa will use its sponsorship of the Rio Olympics to trial wearable payments, Finextra reports. Visa has teamed up with Swatch to develop a watch linked to a prepaid card and enabled for contactless payments. It is also trying out a bracelet called Pulseira Bradesco and ceramic NFC-enabled rings. Venezuelan President Nicolas Maduro has accused Citibank of planning to shut his government's foreign currency accounts and attacked the bank for starting an economic "blockade", Reuters reports. Citibank is major supplier of banking services to the Venezuelan government and conducts the bulk of its foreign currency transactions. The country is already facing an economic crisis, which critics say is the result of the socialist policies of Maduro and his predecessor Hugo Chavez. Reuters was not able to get a comment from Citibank.