The FIA announced this week that the Andretti project had passed the first two phases of the entry process, having been approved by the governing body.
The matter now passes to F1 for a commercial discussion, which will revolve in large part around the potential impact on the finances of the 10 existing teams.
Some drivers have been wary of showing public support for the Cadillac-backed Andretti project given the opposition expressed by current team bosses, and even Hamilton acknowledged that his views might not be popular in the paddock.
"I think it's great," he said when asked by Motorsport.com about the prospect of an Andretti team. "I think in F1 I've always felt that there weren't enough cars on the grid.
"There will definitely be people that won't be happy for me to be so supportive of it! But I think it's great.
"It's an opportunity for more jobs, there's another two seats available for a potential female driver to come through. It opens up more possibilities, and I think it'll be more exciting for the race."
Max Verstappen was also positive, while noting that teams have a different take on the subject compared to drivers.
"That is why it is very hard to comment on that because I speak from the drivers' side," said the Dutchman.
"Of course I am not a team owner, but I can understand their side. But everything I have seen so far, plus I think the partners they have, and the name, they have shown that they are a professional team, so it would be I think it's nice because it gives more opportunities for the drivers' side.
"But I can understand it from the teams' side that they don't want it. So it is a tricky one, a tough one.
"At the end of the day the FIA, the teams and of course the FOM, they have more information about how serious everything is and how well everything is prepared. That is why it is not going to be an easy decision to make."
Fernando Alonso, who drove for Andretti in the 2017 Indy 500, said he would support his Aston Martin team's view on the matter.
"A great team, I know Michael and it will be obviously a great name to add to F1," he said. "But there are other people in charge of these kinds of decisions, and first FIA, and then FOM and the teams as well.
"I don't know exactly what to say. Whatever is the final decision is going to be okay. I like Michael, I like the organisation. But I also understand other things, and I will support as well whatever Aston Martin position is, and I will be okay with anything."
Valtteri Bottas had no qualms about backing the addition of two cars to the grid.
"For me very clear that the sport would be better if there were more cars," said the Finn. "I remember watching as a kid, when you have a bigger grid there's more entertainment, and more opportunities for young drivers as well.
"So for me, it's for sure the more teams the better. Like, I think the upper limit would be probably like, I don't know, 30 or something? But we're far from that. So for me, it would be very welcome. But I know the reasons why there's a bit of pushback."