The Open Arms NGO on Friday shared photographs of the actor and activist taking food and supplies aboard the humanitarian vessel, Efe news reported.
"We are here on the Open Arms boat, I just arrived here from Lampedusa and we have brought as much water and as much food as we possibly can for everyone on board. I think there's about 140 people here, maybe 150," Gere said in a statement.
"Finally, a little good news. Food arrives at #OpenArms and we have an exceptional crewmate #RichardGere," the organization tweeted Friday.
Since last week, the ship has been stranded near the southern Italian island of Lampedusa, in international waters, to be assigned a safe harbour to disembark 121 people who were rescued at sea during two different operations.
The first rescue was on August 1 when 55 migrants were saved, including twin babies and a pregnant woman, just as their boat was about to capsize, founder of the NGO, Oscar Camps, told Efe.
The second was in the middle of the night the day after and 69 people were rescued and welcomed aboard, including two children and two pregnant women.
Italian Interior Minister Matteo Salvini has consistently campaigned to keep ports closed to NGOs, which he accuses of boosting irregular migration and has insisted that he will not allow the Open Arms vessel to enter Italian waters.
Salvini further added that the immigrants aboard were the "direct responsibility" of Madrid.
Spanish Government spokeswoman, Isabel Celaa, said on Friday that Spain wants the Open Arms migrant rescue ship to disembark the 121 migrants on board at the nearest safe port.
The Spanish city of Valencia has offered to host the boat and the southwestern community of Extremadura has agreed to receive the migrants.
( With inputs from IANS )