Sen. Lindsey Graham, R-S.C., said he and 99 other senators believe Russia interfered in the presidential election and "we'll have the hearings and put sanctions together that will hit [President Vladimir] Putin as an individual and his inner circle."

"They're doing it all over the world, not just in the United States," Graham told Jim Sciutto on CNN on Tuesday. "They're interfering in elections and in democratic countries' efforts to self-determination all over the world."

Sciutto interviewed Graham and Sen. John McCain, R-Ariz., from Estonia, where the senators said they were visiting allies to reassure them of the Senate's support to their efforts to beat back Russian aggression.

McCain is chairman of the Senate Armed Services Committee, of which Graham is a member. Amy Klobuchar, D-Minn., who does not sit on the panel, was also on the trip, Graham said.

"Vladimir Putin is a thug and a bully — and I believe that that has become apparent," McCain said. "There is no doubt about it.

"We have to act, and we have to have a policy, which this administration does not have, and a strategy, which this administration does not have, and address this threat to our national security."

"If they're able to undermine an election, they are able, then, to undermine democracy," McCain said.

He added President-elect Donald Trump, who has questioned accusations Russia intervened in the election process, would change his mind based on what he and Graham find on their trip to Eastern Europe.

"I think he will, when presented with the overwhelming evidence, change his view," McCain said. "He has said some things, like he wants to spend more money on defense.

"He has said some favorable things about NATO."

Both senators said they planned to urge Trump to keep American troops in the region, especially if Putin invades Estonia or any other NATO ally there.

"I believe Trump will understand the need for an American presence here," McCain told Sciutto. "He has himself said we need to rebuild the military, which has been harmed dramatically over the last eight years."

Graham reiterated the United States must beat back Putin, as it staves off threats from other rogue nations.

"If we don't push back against Putin, Iran and China — they could hack into our systems," he said. "Today it's Democrats. Tomorrow it could be Republicans, with the Iranians and Chinese.

"Trump says he'll be tough with China. He needs to be."

"We need so show any nation what happens if they try to interfere with our democratic process," Graham said.

"It's the Democrats today. It could be us tomorrow, to my Republican colleagues."