By Hugh Schofield
BBC News, Paris
French officials were angry that a relief flight was originally turned back
Nicolas Sarkozy has moved to defuse a potentially embarrassing row with the US over claims that France is being sidelined in the aid effort in Haiti.
The French president's office praised the US's "exceptional mobilisation" and its "essential role... on the ground".
He was responding to signs of tension that appeared over the weekend.
France's International Co-operation Minister Alain Joyandet complained that a French plane carrying a field hospital was turned back by US troops.
American forces have been running Port-au-Prince airport, and have not been able to accommodate all relief flights.
Mr Joyandet - who was in Haiti - said he had issued a formal protest to the US authorities via the French embassy, and that his actions were backed by Foreign Minister Bernard Kouchner.
He was quoted as saying: "This is about helping Haiti, not about occupying Haiti."
But now the Elysee Palace has issued a statement explicitly praising the US for its lead role in the emergency, and denying any breakdown in relations.
France has issued a stamp in solidarity with victims in Haiti
The statement says that Mr Sarkozy has had a telephone conversation with US President Barack Obama, in which they pledged to "unite their efforts to confront the urgent humanitarian situation, and, later, to respond to the vast task of reconstruction".
Underlying the episode is a tangible sense of hurt pride that France is being relegated to a secondary role in a country long regarded as part of its own sphere of influence.
France was colonial master in Haiti up until the famous slave revolt 200 years ago, and French is still an official language there.
The crisis has unleashed a vast outpouring of support and sympathy in France, which is home to some 80,000 Haitian nationals.
Charities have received more than 15m euros (£13m) from private donors - in addition to the 20m euros provided by the government.
France has also sent 240 emergency workers and police to help with the rescue effort, while two navy ships and five aircraft shuttle in supplies.
However, the fact that the United States is so clearly in charge of the operation does rankle with some in France - particularly those with a predisposition to mistrust anything American.
As one blogger put it on the website of Le Figaro newspaper: "The US aid to Haiti constitutes a new case of 'shock doctrine' - ie taking advantage of a natural calamity to subjugate a disorientated populace to the desires and orders of a financial and industrial oligarchy."
However most French people are far less hostile - recognising that Haiti is in America's backyard, and that America alone has the resources to react on the scale required.