Charlie Sheen to Denise Richards -- You're a Heartless, Ugly Hag

Denise just responded to the story via Twitter ...

Charlie Sheen has declared nuclear war on his ex-wife Denise Richards ... blasting her as a "heartless" and "ugly" hag who's holding their children hostage.

Sheen just blasted Richards ... again ... this time, he's furious that Denise won't let their children visit him to exchange Christmas gifts.

Charlie expressed his anger in a series of texts ... saying, "lemme see if I got this straight; you won't even spring the girls for 30 mins, from the 10 mil house I gave you, (100 yds away) to come down and open the gifts their dad bought them before they leave??"

"I hope your stocking is bronze-age coal stuffed along with an assortment of 8x10's of yours so you can see how despicable and heartlessly ugly you and your fermented soul continue to be."

He added, "hash tag. hag shag."

Charlie also says despite the fact Denise won't let him see the kids, she had the "audacity" to ask him to borrow his private jet to go on the big family trip that she banned him from.

Charlie says he went to Denise's home to plead with her to change her mind and to deliver gifts to the kids, but was not allowed to see them.

Charlie concludes, "This is the worst Xmas I've ever had."