The British fighter's rematch with the former world champion was called off in 2023 after he returned "adverse analytical findings" in a drugs test but he has since returned to the ring and would be open to another fight against Joshua - who is searching for an opponent following Tyson Fury's retirement.
Whyte, who beat Ebenezer Tetteh last month, told Sky Sports: "[Joshua] Sounds perfect for me. They don't need to ask me twice. They talk about me as an option, but they haven't said anything to me, so it's just negotiation tactics from them. But I'm up for the fight and I'm ready to fight again.
"If he wants to fight, then all they've got to do is call me. I'm always up for fighting AJ. No problem for me."
However, Whyte believes that Joshua is "finished" following his bruising defeat to Daniel Dubois in their world title fight last September.
He said: "Personally, I think he's finished.
"I think he made a huge mistake not taking the immediate rematch with Dubois. It was a world title fight, a great payday and the perfect opportunity to avenge his knockout loss. He will forever have to suffer the memes of being face-planted at Wembley by Dubois.
"When I lost to [Alexander] Povetkin, on the way back to my dressing room, I crashed Eddie Hearn's live interview and demanded the immediate rematch. Nothing else mattered until I beat him in the rematch. It's a mindset thing. I want to fight AJ and Tyson again because they both beat me, although it's one-all with AJ (Whyte won their fight at amateur level)."