A single U.S. senator is threatening to delay the expected confirmation of Senator Hillary Clinton as secretary of state when the Senate convenes later Tuesday.

Unanimous consent votes are possible Tuesday on various Cabinet nominees of President Barack Obama.  But a Republican senator from the southern state of Texas, John Cornyn, said he will not give such consent for Senator Clinton.

Cornyn said he is not satisfied with Clinton's responses to questions about her husband's foundation.  

Former U.S. President Bill Clinton runs a charitable organization called the Clinton Foundation. Cornyn said he wants Senator Clinton to increase oversight of Mr. Clinton's international fundraising efforts to prevent governments from trying to sway U.S. policy through donations.

The Senate Foreign Relations Committee on Thursday approved Ms. Clinton's nomination as the next secretary of state by a vote of 16-1.  The full Senate was expected to confirm her nomination Tuesday shortly after President Obama's inauguration.

If Senator Cornyn does indeed withhold his consent, a full roll call vote likely will be held on Wednesday.  Ms. Clinton is expected to receive bipartisan support for her confirmation at that time.

Some information for this report was provided by Reuters.