The damage has been estimated at 1.956 billion euros, France's overseas affairs ministry said in a statement as Minister Annick Girardin travelled to Brussels to seek EU assistance.
The EU Solidarity Fund (EUSF) will disburse 50 million euros to the two islands, Girardin said after meeting with EU economic affairs commissioner Pierre Moscovici.
The commissioner said 10 percent of the funds would be released "before Christmas".
The wealthy French island of St Barthelemy, which was also severely hit by the two Category Five hurricanes, is ineligible for aid from the EUSF and was not included in the damage assessment.
The EUSF sets country-by-country thresholds for eligibility based on gross national income.
Irma, which struck on September 6, killed at least 11 people on St Martin and St Barthelemy -- an upscale tourist hotspot also known as St Bart's.
Less than two weeks later, Maria ravaged Guadeloupe, killing at least two, and Martinique, but it caused the worst damage in Dominica and on the US island of Puerto Rico.