Obama campaign adviser David Axelrod had a single question for Mitt Romney when it comes to the debt limit, and Sen. Mitch McConnell's (R-Ky.) plan to avoid default: "Why so quiet?"

Axelrod pestered Romney, former Massachusetts governor and Republican presidential candidate, for his relative silence on some of the more pressing issues surrounding the debate over whether to raise the nation's debt limit.

He tweeted:

Anyone heard from Mitt Romney lately? Where is he on McConnell plan? On the debt talks? On the impact of a default? Why so quiet?

Eric Fehrnstrom, a senior adviser on the Romney team, tweeted a question of his own in response:

I have a question for @davidaxelrod: Where are the jobs? We're not just on wrong track; it feels like we're tied to the tracks

Romney's campaign has said it's not interested in weighing in on the day-to-day changes in negotiations over whether to raise the debt ceiling, since no plan is really being put forth.

But other Republicans have taken notice of Romney's quiet approach and have called on him to stake out a clearer position. McConnell, the Senate minority leader, offered a fallback plan to avert default that has drawn criticism from some presidential contenders.

—This post was updated at 6:20 p.m.