Argentina missed interest payments to international creditors on Friday, thrusting the economically besieged country back into default territory. But there was cautious optimism among analysts - and the government - as talks to restructure $66bn in foreign debt appeared to be making headway. If the new deal happens, it could stave off a more dramatic financial unravelling. The country officially extended the Friday deadline for its external debt offer to June 2 "in order to continue constructive discussions", Economy Minister Martin Guzman said in a statement. The initial offer called for a three-year grace period on payments, a 62 percent reduction in interest payments and a 5.4 percent cut to the principal. It was rejected by key groups of bondholders, who have presented counterproposals. Reuters reported that Argentina intends to amend its offer in the coming days.