South Carolina Sen. Lindsey GrahamLindsey Olin GrahamGOP sees debt ceiling as its leverage against Biden DACA court ruling puts weight of immigration reform on Democrats Senate braces for a nasty debt ceiling fight MORE (R) said Wednesday he would lead a charge to investigate Russia's interference in the U.S. election and hacks on the Democratic Party.

"I think [Donald] Trump should take a real tough tone with Russia, because if he doesn't, you're going to allow Russia to begin to break apart alliances," Graham told CNN's Manu Raju.

The Republican senator also said he hoped to use his leadership role on two subcommittees to launch a deeper investigation of Russia's hacks, CNN reported. Graham chairs the State, Foreign Operations and Related Programs subcommittee and the Crime and Terrorism subcommittee.

Raju said Graham told him that he and Sen. John McCainJohn Sidney McCainMeghan McCain on Pelosi, McCarthy fight: 'I think they're all bad' Democrats seek to counter GOP attacks on gas prices Biden nominates Jeff Flake as ambassador to Turkey MORE (R-Ariz.), chair of the Armed Services Committee, will travel to Eastern Europe to investigate Russian meddling in other countries' elections.

During the campaign, Graham was a strong GOP critic of Trump, including on his friendlier stance toward Russia, and chose to vote instead for independent candidate Evan McMullin.