Sarkozy was speaking after talks with Greek Prime Minister George Papandreou, who is looking to secure pledges of support from European capitals that will reassure markets and lower the debt-stricken country's high borrowing costs.
"If Greece needs help, we will be there," Sarkozy said at a joint news conference.
"The main actors on the European stage [have] decided to do whatever is needed to make sure Greece is not isolated," he added, declining to give precise details of any aid plans but stressing that his economy minister was drawing up measures.
"Christine Lagarde, in tandem with her colleagues in the euro zone and in Europe [...] is working on a certain number of precise measures if Greece needs them," he said.
Papandreou met German Chancellor Angela Merkel and Luxembourg Prime Minister Jean-Claude Juncker on Friday. He had been hoping for specifics of a possible aid package and on Sunday told reporters he saw the outlines of a plan.
"After my meetings more specific ways are beginning to emerge about how to deal with any possible borrowing problems," he told reporters. He is due to fly to Washington later on Sunday for meetings with US leaders.
Sarkozy talked to Merkel earlier in the day by telephone and said that France, Germany and Greece were ready to take concerted action against market speculation aimed at Greece.
Sarkozy agreed that speculators were artificially hiking the cost of borrowing for Greece and said they needed to be tackled.
"This problem could hit lots of countries if we don't come up with a collective response," he said.
"Concrete, precise means exist [to combat speculators] which we won't be communicating tonight [...] but which at the given moment will show that Greece is not just being supported politically, but also in all aspects of any eventual requests."
Towards a European IMF
Meanwhile, German Finance Minister Wolfgang Schaeuble said in a newspaper interview released on Saturday (6 March) that he plans to make proposals soon on a new European institution to help ensure the stability of the euro zone.
"We are not planning an institution in competition with the International Monetary Fund but for the internal structure of the euro zone we need an institution that commands the experience of the IMF and similar executive powers," Schaeuble told Welt am Sonntag. "I will make proposals on this soon."
Schaeuble said he favoured stronger EU economic policy coordination and that he was working with EU and G20 partners to push for improved transparency of credit default swaps.
"We cannot allow our joint currency to become a ball for international speculators to play with," he said.
(EurActiv with Reuters.)
