Sen. John Thune is giving himself a short window — 32 days from now — for making a decision on whether to run for president. The South Dakota Republican told talk radio host Hugh Hewitt on Wednesday he wants to decide by the end of February.

Thune, the Republican Policy Committee Chairman, said his low name identification nationally would necessitate that he launch his White House bid sooner rather than later, should he decide to run. The Senator has said in previous interviews that he was likely to make his decision by spring.

“I’ve told people I don’t have a definite timeline or deadline out there,” Thune told Hewitt, according to a transcript of the interview posted on the host’s website. “But it strikes me, at least, for somebody like myself who’s not known, and would have to work a lot harder at getting known, that sometime in the next month or two, but for sure probably at the end of next month, we’d have to let folks know our intentions.”

Thune has spoken with Sen. John McCain (R-Ariz.) and others about a potential bid, but he has left some early state Republicans wondering if he is serious in his efforts.