Sen. John McCain, R-Ariz., condemned provocations by the Russian government in the strongest of terms Friday, calling the Kremlin's interference in the U.S. elections process an "act of war."

The chairman of the Armed Services Committee made the comment during a visit to Ukraine, a country that is no stranger to Russian cyberattacks.

"When you attack a country, it's an act of war," the Arizona senator said on a Ukrainian TV channel, according to a Reuters report.

"And so we have to make sure that there is a price to pay, so that we can perhaps persuade the Russians to stop these kind of attacks on our very fundamentals of democracy," he added.

On Thursday, the Obama administration announced sanctions against Russia in retaliation against the cyberattacks, including the expulsion of 35 diplomats.

McCain, along with Sen. Lindsey Graham, R-S.C., released a statement afterwards calling on Congress to impose stronger sanctions on Russia, saying Obama's "long overdue" sanctions" are "a small price for Russia to pay for its brazen attack on American democracy."

McCain's hard-line condemnation of Russia is a break from the attitude of the incoming Republican president, Donald Trump. On Thursday Trump urged Americans to "move on," but said he would nevertheless meet with intelligence officials in order to be fully apprised of the situation.

Putin has said Russia will not retaliate against Obama's sanctions in what appears to be a gesture of goodwill towards Trump's incoming administration beginning Jan. 20. This pledge elicted praise from the president-elect, who tweeted Friday, "Great move on delay (by V. Putin) — I always knew he was very smart."

The Armed Services Committee will convene a hearing on Thursday morning about foreign cyberthreats to the United States. The witnesses expected to testify are James Clapper, the director of national intelligence, Marcell Lettre, the undersecretary of defense for intelligence, and Adm. Michael Rogers, the head of both U.S. Cyber Command and the National Security Agency.

On Friday it was reported that U.S. officials believe Russian hackers also breached the U.S. electric grid.