Hamilton will take Sainz’s seat alongside Charles Leclerc at the Italian glamour team next season in a shock move announced earlier this month.
"I think this is how the sport works and obviously I have a lot of respect for Lewis and the success he’s had and obviously his choice to join Ferrari," said Sainz sitting alongside Hamilton in a Bahrain Grand Prix press conference on Wednesday.
"I would have done the same in his position," he added, who himself replaced four times champion Sebastian Vettel at the Maranello-based team in 2021.
Hamilton, who has not won a race since 2021, signed a two-year extension with Mercedes only last August but activated a break clause to sign a multi-year deal with Ferrari.
He has said he wanted to start a new chapter in his record-breaking Formula One story.
Ferrari are the sport’s most successful team but have not won a drivers’ title since Kimi Raikkonen’s 2007 championship.
"There’s a huge amount of respect between us all and I have a huge amount of respect for Carlos," said the 103-time race winner. "I don’t feel like there’s any animosity or anything like that.
"It’s not a personal thing, it’s what happens in this racing world and I hope that nothing changes between us through that,” added Hamilton. "I don’t think it will."
