President-elect Donald TrumpDonald John TrumpIvanka Trump pens op-ed on kindergartners learning tech Bharara, Yates tamp down expectations Mueller will bring criminal charges Overnight Cybersecurity: Equifax security employee left after breach | Lawmakers float bill to reform warrantless surveillance | Intel leaders keeping collusion probe open MORE on Wednesday took a swing at Republican Sen. Lindsey GrahamLindsey Olin GrahamDurbin: I had 'nothing to do' with Curbelo snub Republicans jockey for position on immigration Overnight Health Care: House passes 20-week abortion ban | GOP gives ground over ObamaCare fix | Price exit sets off speculation over replacement MORE (S.C.) when asked about the lawmaker's plan to propose tougher sanctions against Russia.

When asked what he thinks about Graham's call for tougher measures at his Tuesday press conference, the president-elect said that he did not hear about the senator's proposal, while taking a swipe at his former GOP rival.

"I haven't heard Lindsey Graham is going to do that. Lindsey Graham, Lindsey Graham, I've been competing with him for a long time. He's going to crack that 1 percent barrier one day," Trump quipped.

"I didn't realize Lindsey Graham is still at it. I think Lindsey Graham is a nice guy, actually. I've heard that he is a nice guy, and I've been hearing it."

Graham dropped out of the crowded GOP presidential race in December 2015 and has been one of Trump's toughest Republican critics.

He has been one of the loudest GOP voices in calling for strong measures against Russia over its meddling in the U.S. election, and he has signaled that he will not vote for a Trump Cabinet nominee that rejects U.S. intelligence on Russia.

Trump's pick for secretary of State, former ExxonMobil CEO Rex Tillerson, faced tough questions about his connections to Russia as he began his confirmation hearing Tuesday.

Graham has urged the president-elect to strengthen his policy toward Moscow, especially in light of intelligence agencies' findings that the Kremlin intended to interfere with the presidential election to help Trump win the White House. 

“I think he's worried that inquiring into what Russia did in the election is going to undermine his credibility and his legitimacy,” Graham said on Sunday.

“Quite frankly, I haven't heard any Democrat at all of prominence say that we doubt that Donald Trump won,” he added.

Trump said at his press conference that he does believe that Russians were behind the hack on the Democratic National Committee and others, while also pointing to other countries including China.