(Image Credit: Dimitrios Kambouris/WireImage for Marc Jacobs/Getty Images)

The war of words between two of music's biggest divas is ramping up after Lady Gaga added fuel to the fire by responding to Madonna's latest dig.

At a concert in New Zealand, Gaga responded to Madonna for stirring up the "haterade": "It sometimes makes people feel better about themselves, to put other people down, or make fun of them, or maybe make mockery of their work, and that doesn't make me feel good at all."

What did Madonna do to get a reaction out of Lady Gaga? Madonna performed a mash-up of her 1980s hit "Express Yourself" and Lady Gaga's "Born This Way" during a May 31 concert in Tel Aviv.

"I'm on the right track, baby, I was born this way. Express yourself," Madonna sang.

This feud began in January when Madonna dissed Lady Gaga's sort of-sound-alike track and described it as "reductive" to ABC News' Cynthia McFadden. That's when things got global and even body parts got involved.

A wayward pole clubbed Lady Gaga, 26, in the cranium, but she soldiered on and finished the routine despite telling her audience she might have a concussion. Not to be one-upped, Madonna proudly showed her breast at a concert in Istanbul, Turkey, in front of 55,000 screaming fans June 7.

Was it a stunt? Some observers on Twitter are calling it just that. Remember, this is Madonna, 53, we're talking about. Anyone who complains about Madonna's choosing to expose herself onstage is the real boob.

At one time, the two pop goddesses shared the "Saturday Night Live" stage. "What the hell is a disco stick?" Madonna asked at the time.

It was all in frisky fun, but the two seem to be waging in a worldwide cold war of epic proportions.