Republican presidential candidate Mitt Romney called Wednesday for an across-the-board cut in individual tax rates and the elimination of the Alternative Minimum Tax.

The former Massachusetts governor said that, as president, he would direct Congress to make up for any lost revenue by limiting existing deductions, particularly those for wealthier Americans. Romney aides, speaking ahead of a planned speech on the subject by the candidate, did not say which deductions would be targeted. The plan is intended to be revenue neutral, Romney aides said.

Mr. Romney is unveiling the latest details of his economic blueprint at a critical juncture in his White House bid, with rival GOP candidate Rick Santorum presenting a strong challenge to him ahead of primary elections in Michigan and Arizona on Tuesday. Mr. Romney needs strong showings in both statesto reclaim his front-runner status.