The Argentine central bank on Friday declared a complete and indefinite suspension of all banking activity in the country, in a sign of its desperation at money leaking out of the shattered financial system. The bank said the suspension of all deposit and foreign exchange operations would begin immediately following the close of business on Friday. Although temporary halts have been called before, this is the first complete freeze since the country plunged into crisis around the turn of the year, following a default on its external debt and the suspension of International Monetary Fund crisis lending.