Russian Finance Minister Anton Siluanov said on Thursday he was confident a "reasonable solution" would be found for Visa and Mastercard after the credit and debit card companies complained about tightened regulations in Russia. Visa and Mastercard have stopped serving several Russian banks because of U.S. sanctions and Russia has obliged them to pay a security deposit of 25 percent of their average daily turnover in Russia to the central bank once a quarter from July 1 - a move that the U.S.