Cruz has studiously avoided publicly criticizing the Republican front-runner, and Trump had previously spared Cruz from his trademark attacks. But the newest exchange comes after a New York Times report that Cruz suggested to donors in a private meeting that he doubted Trump’s “judgment” to be commander in chief.

Cruz’s campaign called that report “misleading” on Thursday, but did not dispute the nature of Cruz’s emphasis on “judgment.”

“In the course of a Presidential election, the voters are going to make a decision about every candidate,” the campaign said in a statement. “And ultimately the decision is, who has the right judgment and the right experience to serve as Commander in Chief?”

While Trump continues to lead in national and most early state polls, Cruz has recently gained significant ground in the key first caucus state of Iowa.

This article originally appeared on NBCNews.com.