Liz Cheney said Wednesday that Sen. Mike Enzi, her rival in the suddenly contentious Republican Senate race in Wyoming, was "just confused" when he told reporters Tuesday that he was unaware she was considering running against him next year.

"It's not true," Cheney told reporters in Casper as she formally announced her candidacy. "I did not tell Senator Enzi I wouldn't run if he did."

"I think Senator Enzi may be confused," Cheney said, speaking at a press conference when she outlined her reasons for challenging the three-term incumbent. "What happened is, I called Senator Enzi to tell him that I was considering a run, and I have always believed that that decision should be made irrespective of whoever else is in the race." Decisions to run, she added, should be "based on what you think you bring to the cause based on the issues and the policies that matter."

On Tuesday after Cheney, 46, had announced her intentions to challenge Enzi for the U.S. Senate seat in Wyoming, Enzi told reporters, "She said that if I ran, she wasn't going to run, but obviously that wasn't correct."

He added, "I thought we were friends."

Cheney moved to Wyoming last year with her family to eye political opportunities. She had hoped Enzi would retire, but when he formally announced his re-election earlier Tuesday, she suddenly announced she would run too, a decision that sets the stage for a contentious Republican primary fight.

At the press conference officially launching her campaign, Cheney said that Enzi may have her "mixed up with Cynthia Lummis … he said something exactly the opposite to this just last week in The New York Times." Earlier this month a story in The New York Times mentioned a recent local interview with Rep. Cynthia Lummis, the state's at-large Republican congressman, in which she said she would support Enzi if he ran again but if he made the decision to retire she would run. This may have been what Cheney was referring to Wednesday.

After the announcement Tuesday, Lummis repeated that she would support Enzi calling Cheney "the shiny new pony" in Wyoming politics, telling reporters, "I don't think she's going about it the right way."

"In the instance where you have the three-term sitting U.S. senator who has done nothing to merit a primary challenge and you challenge that person without the courtesy of calling them just before you make the announcement, it's just not the best way to start a campaign."

On CNN Wednesday, Enzi stressed that he is "absolutely not too old to be senator. I'm the median age."

"I'm only surprised in that she said if I ran, she wouldn't. She announced 30 minutes after I more specifically stated my intention," he told CNN.

At the event today at the Parkway Plaza Hotel & Convention Center, Cheney also said she is running because it is "time that we stand up and fight. That we can't go along to get along. We can't sort of say that we are going to accept business as usual."

"I care very much about the values that the state of Wyoming was founded, because I care deeply about our freedoms because I'm worried very much that they are under assault by the federal government," Cheney said. "I'm going to be spending the next 15 months or so really focused on issues and substance and running the kind of campaign that I think the voters here deserve. So, I'm focused on earning every vote I can, you know, the way it ought to be done here in Wyoming, which is one person at a time."

Enzi's office did not immediately respond to a request for comment.