United are reportedly prepared to rival Chelsea for West Ham star Rice at the end of the season.
But Moyes denied West Ham have received an offer for the 22-year-old, who can play in midfield or defence.
"They're not true [rumours of a bid], we've had no contact from either of those clubs regarding Declan and we wouldn't want any anyway," Moyes told Amazon Prime after West Ham's 1-0 victory over Burnley on Saturday.
"He's doing great for us, he's a big leader now, he's taken a lot of the weight off Mark Noble. He's turning out to be a really good player but also a really good boy and good around the club."
Rice left boyhood club Chelsea for London rivals West Ham in 2014 after being released at the age of 14.