Story highlights Dean Heller has been a vocal critic of Republicans' legislation to overhaul Obamacare

The Nevada senator talked to President Donald Trump this week about attack ads

Washington (CNN) Republican Sen. Dean Heller is having discussions with Senate leaders about the GOP health care bill that he opposes -- but for now, he doesn't want to show his cards.

"I'm not going to tell you," Heller told CNN on Thursday, when asked what kind of negotiations he has been having with Senate Majority Leader Mitch McConnell. "I'm not going to negotiate with the press here on what it's going to take to get to something favorable for the state of Nevada."

Heller has been one of the most vocal critics of the GOP legislation to overhaul Obamacare, and is one of nine Republican senators who have said they oppose the bill in its current form. With McConnell working furiously to get 50 "yes" votes on the bill, Heller and some of his colleagues have been reticent to discuss those private conversations with reporters in recent days.

One topic Heller didn't want to discuss: his conversation with President Donald Trump this week about a pro-Trump group's attack ad against him.

"I don't want to talk about it," Heller said, when asked what he said to Trump about the ad when he visited the White House this week. "It's a private conversation."

Read More