"There are people who have lost everything, who are destitute, there are people who are laid off and we are going to set up a [system of aid] so that next Monday at the latest there will be payments," Macron said on the second day of his visit.
The delay was because "I don't want there to be fraud, abuses and so on", he said in a video posted on his Facebook page.
Extra flights between mainland France and the main French island of Guadeloupe will provide 1,000 extra places by the end of the week, Macron promised, pledging that fares will be no higher than 250 euros.
In response to looting that took place on Saint-Martin after the hurricane, Macron that 3,000 security forces would be deployed on the island by the end of the week.
A curfew on the island has been extended to 21 September.
The president also promised that electricity supply would be reestablished in key areas by the end of the week and the supply of drinking water would be restored as from 20 September, although in lower volumes than before the hurricane hit.
The government has been accused of being slow to respond to the disaster, which caused widescale destruction and cost at least 11 lives on the French Caribbean islands.
Other people are still missing but the seven people who were hospitalised with serious injuries were out of danger by Wednesday, according to Health Minister Agnès Buzyn, who accompanied the president on his visit.
Macron hit back at his critics, claiming that the government had "responded as soon as the information was given" and had continued to do so "for the length of this crisis".
In France Prime Minister Edouard Philippe told France 2 television that he was "extremely proud of the reaction of public services" and said he was happy to face a parliamentary commission if one is established.
While supplies continue to be flown in, a French navy vessel, BPC Tonnerre, left the port of Toulon on Wednesday with personnel, equipment and 116 vehicles on board.
On leaving Saint-Barthélemy, which has been less seriously affected than Saint-Martin, Macron tweeted an appeal to tourists to visit the island "as soon as possible, because tourism is the heart of its economy".