U.S. Sen. Richard Burr is opposing the nomination of a new Treasury secretary.

The Winston-Salem Republican said in a statement that he has given "the benefit of the doubt" to President Barack Obama's Cabinet nominations so far and he has been pleased with many of them.

But he said he was troubled by nominee Timothy Geithner's tenure on the New York Federal Reserve, especially his support for what Burr called the "ill-conceived" proposed merger of Citigroup and Wachovia. 

"During his tenure at the New York Federal Reserve, Mr. Geithner was a leading participant in many late-night, closed-door deals made between major financial institutions and the federal government," Burr said in a statement.

In addition, Burr said he was troubled by Geithner's failure to pay self-employment taxes while working for the International Monetary Fund.