BRUSSELS (AP) - Greek Prime Minister Alexis Tsipras renewed his diplomatic offensive on Wednesday to try to convince European creditors to pay out the bailout loans the country needs to avoid default.

The creditors have made it clear that Greece has to improve its offer of economic reforms before they release 7.2 billion euros ($8.1 billion) the country needs to pay debts due at the end of the month.

Tsipras had short meetings with EU Commission President Jean-Claude Juncker, German Chancellor Angela Merkel and French President Francois Hollande on the sidelines of a European Union-Latin America summit late Wednesday and planned to continue talks with Juncker today.

Wednesday's talks came after Juncker's European Commission had said the offers made by Greece last week were still not good enough to unlock the bailout funds.

"For this final push, the Commission is of the view that the ball is clearly now in the court of the Greek government," Commission spokesman Margaritis Schinas said.

With the onus firmly on Greece and options increasingly limited, Standard & Poor's in New York downgraded Greece's credit rating 1 notch further into junk territory.

Finance ministers from the 19 nations using the euro currency will meet in Luxembourg next week with the Greek deadline for payment ever closer.

The lack of visible progress in the negotiations over the past weeks has revived fears Greece could default on its debts and drop from the euro, a move that would create huge uncertainty for Europe and global markets.

"The goal is to keep Greece in the eurozone," Merkel said. "Where there is a will, there is a way." Yet she insisted it was up to Tsipras first and foremost to show that willingness.

Greece has three weeks left to conclude a deal with its creditors before its bailout program expires at the end of the month, when it will also have to repay about 1.6 billion euros ($1.8 billion) to the International Monetary Fund.