He added, however, that Greece would not necessarily make a formal request for help.
On Sunday, the eurozone and International Monetary Fund (IMF) agreed details of a loan package to help debt-ridden Greece.
Concerns about Greece's high levels of debt have put pressure on the euro.
The currency fell by 1 cent against the dollar on Thursday, and slipped a further 0.54% on Friday to close at $1.3506.
On Tuesday, Greece successfully raised 1.56bn euros ($2.1bn; £1.4bn) in an over-subscribed issue of bonds, designed to raise money to repay some of its debt.
However, the country's finance ministry said on Thursday that it had written to the European Union, European Central Bank and IMF to discuss the rescue plan.
The IMF's managing director, Dominique Strauss-Kahn, responded to the letter, saying he would send a team to Athens on Monday to begin negotiations.
Many analysts believe Greece will have little choice but to ask for help as it will not be able to raise enough money, at an affordable rate, to pay off its debts.
Greece needs to borrow about 11bn euros by the end of May, and a total of 54bn euros by the end of the year.