Corker, ranking member of the Senate Foreign Relations Committee, sent a letter to President Obama Monday asking about information regarding cash payments to Karzai. He said Karzai was told by the CIA the payments were ongoing.
Corker said he would place $75 million in U.S. government funding for Afghan election programs on hold until he gets information about the payments from the White House.
"I have determined that the further commitment of taxpayer funds at this time toward such an incoherent governance strategy would not be in our national interest," Corker said in a statement.
Afghanistan holds elections next year as international forces end their war-time commitments to a NATO-led mission. Past elections were seen as skewed in Karzai's favor.
NATO Secretary-General Anders Fogh Rasmussen announced from Kabul national forces in Afghanistan have taken the lead in all security operations in the country.
Rasmussen said international forces would transition to a mission to train, advise and assist Afghan security forces. A military relationship with Afghanistan next year will be "based on a new relationship, that will remain strong for years to come," he said.