In a televised interview Thursday evening, senior US Senator Lindsey Graham called for "somebody in Russia" to assassinate President Vladimir Putin after Moscow's invasion of Ukraine, AFP reported.

"How does this end? Somebody in Russia has to step up to the plate... and take this guy out," the senator told Fox News.

He repeated the call later in a series of tweets, saying "the only people who can fix this are the Russian people."

"Is there a Brutus in Russia?" asked the senator, referring to one of Roman ruler Julius Caesar's assassins.

The former US presidential candidate also wondered if "a more successful Colonel Stauffenberg" existed in the Russian military, alluding to the German officer whose bomb failed to kill Adolf Hitler in 1944.

"You would be doing your country—and the world—a great service," he added.

Lindsey Graham had earlier in the day introduced a resolution condemning the Russian president and his military commanders for committing "war crimes" and "crimes against humanity."