Greek Prime Minister Alexis Tsipras held a new round of late-night talks with the leaders of Germany and France and agreed to intensify negotiations with Athens’ creditors ahead of a looming default at the end of the month. As ratings agency Standard & Poor’s downgraded Greek bonds deeper into junk status, questioning whether Athens can pay its debts, the leftist leader emerged early on Thursday from talks on the sidelines of a summit in Brussels with Chancellor Angela Merkel and President Francois Hollande to express confidence.