Moyes was given the unenviable task of replacing Alex Ferguson at United, but he lasted just 10 months before being sacked in April 2014.
But the Scot felt it could have been different if he managed to complete the transfers he targeted, stating he felt United had abandoned their traditions of signing players of the highest calibre.
He claimed he convinced Kroos to move to Old Trafford, but the playmaker eventually opted to stay at Bayern Munich before moving to Real Madrid the following summer.
“Toni Kroos was agreed to come in the summer,” Moyes told reporters.
“I had agreed it with Toni himself and his agent.”
Moyes also said he wanted to sign Bale, revealing United offered more than the then world-record fee of £85.1 million Madrid paid Tottenham.
“When I first went in my real target was Bale,” the Sunderland manager said.
“I felt all along that Bale was a Manchester United player. I fought right until the last minute. We actually offered a bigger deal than Real Madrid.
“But Gareth had his mind made up on going to Real Madrid. That was, in my mind, the player I really wanted to bring to Manchester United.”
As for Ronaldo, Moyes said: “I remember when I first met Sir Alex and he always said there was a chance Ronaldo might come back.
“So that was the level we were targeting.”