By Renee Maltezou and Jan Strupczewski ATHENS/BRUSSELS (Reuters) - Greek Prime Minister Alexis Tsipras said he was willing to accept unpalatable compromises to secure a deal with international creditors, provided he gets debt relief in return, something that Germany refuses to countenance. With Greece heading towards possible default and bankruptcy, he told his negotiating team before it took a counter-proposal to Brussels that without debt relief he would say "no" to any settlement with the EU and IMF that isolate his country from the rest of Europe. In little more than a fortnight, Athens must repay 1.6 billion euros to the International Monetary Fund with money it does not have.