The New York Times reported last week that Ensign helped Doug Hampton get lobbying work and then assisted his clients with government agencies. Ensign has said any actions he took on behalf of Hampton's clients were not done at Hampton's request.
Asked outside his office Tuesday if he had plans to resign, Ensign said, "No, definitely not," the Times reported.
"I feel very confident that when all of this stuff is thoroughly vetted that everything will work out just exactly like I said: that we complied strictly with all the rules and laws of the ethics of the Senate," Ensign said Tuesday.
The Senate Ethics Committee is investigating Ensign, and the FBI is expected to launch a probe, the Times said. Republican leaders have not come to Ensign's support, with Minority Leader Mitch McConnell, R-Ky., saying only that he "continues to serve."
"I am focused on doing my work," Ensign said.