(CNN) Minnesota Sen. Amy Klobuchar said she's not entering an alliance with any of her rivals, including the campaign of former Vice President Joe Biden, whose aides have raised the idea of forging a pact at next week's Iowa caucuses if one of them isn't viable in certain precincts across the state

"I'm not even getting to that point yet. I want to be viable in every precinct," Klobuchar told CNN on Tuesday night in Council Bluffs, Iowa.

It's a conversation that often takes place in the closing days of the Iowa caucuses, when a voter's second choice becomes a critical piece of the political -- and mathematical -- equation. Candidates must reach a threshold of 15% support in each precinct to be viable. If they do not, supporters can resort to their Plan B.

The New York Times reported late Tuesday evening that a top Biden aide in Iowa made an overture this week to the Klobuchar campaign, hoping to win over her supporters in parts of the state where she may not be viable. Two Democratic sources confirmed the discussions to CNN.

The campaign of Pete Buttigieg, the former mayor of South Bend, Indiana, also has its eye on Klobuchar supporters. Biden, Buttigieg and Klobuchar are competing for some of the same supporters, particularly voters looking for a more pragmatic nominee.

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