Sen. Lindsey Graham (R-S.C.) has no intention of backing off his efforts to get to the bottom of questions about former Vice President Joe Biden, his son, Hunter, and the Ukrainian natural gas company that employed the latter on its board for tens of thousands of dollars per month, at least according to a statement Graham made on Monday.

On Friday, Joe Biden, a current presidential candidate, said that he was "angered" and "disappointed" that Graham — his former Senate colleague — would be looking into his interactions with the Ukrainian government while his son was sitting on the board of the Ukrainian natural gas company, Burisma Holdings.

"Lindsey is about to go down in a way that I think he's going to regret his whole life," the 2020 Democratic candidate told CNN. When asked if wanted to say anything directly to Graham, Biden responded, "I say Lindsay, I'm just embarrassed by what you're doing. For you!"

Graham, however, made it clear that he was going to continue looking into the matter in a tweet sent Monday morning, which said, "I love Joe Biden as a person but we are not going to give a pass to what is obviously a conflict of interest.

"I believe Hunter Biden's association on the Burisma board doesn't pass the smell test," Graham added. "If a Republican was in the same position, they'd certainly be investigated!"

Questions about Hunter Biden's employment on Burisma's board and Joe Biden's influence on the firing of a top Ukrainian prosecutor who was investigating the company have been at the center of the Ukrainian controversy and subsequent impeachment fervor that has dominated things in Washington over the past few months.

Graham, who asked the State Department for documents and records related to Burisma and the Bidens on Thursday, is the third Senate committee chairman to start looking into the matter, behind Finance Committee Chairman Chuck Grassley (R-Iowa) and Homeland Security and Government Affairs Committee Chairman Ron Johnson (R-Wisc.), who asked the State Department for records regarding the matter weeks ago.