Athens needs the agreement to unlock more funds to repay the IMF loan due at the end of the month or face a default and a potential exit from the single currency euro. It has so far been unable to agree on several key issues, like pension cuts and a higher budget surplus.
Flambouraris assured Greek reporters that the ECB would not let Greek banks collapse, the BBC said.
The remark came after German Chancellor Angela Merkel stressed that a deal between the Greek and international negotiators must come before the Monday meeting.
On Friday, the ECB provided banks in Greece with an undisclosed amount of financial aid following a week of withdrawals from bank accounts. Greek financial website Euro2day said around $1 billion was withdrawn on Friday alone.