REUTERS

If Donald Trump fails to do so, “I will work with my colleagues to codify sanctions against Russia into law,” McCain wrote.

The Senator reminded that in just the last three years under Vladimir Putin, "Russia has invaded Ukraine, annexed Crimea, threatened NATO allies, and intervened militarily in Syria, leaving a trail of death, destruction, and broken promises in his wake."

Read alsoSenators McCain, Graham urge Trump to punish Russia over hackingHe recalled the death toll of Russia’s war in Ukraine at 10,000 Ukrainian soldiers and civilians. "Russia supplied the weapons that shot down a commercial aircraft over Ukraine and killed 298 innocent people," he added.

McCain emphasized that Russia had conducted a massive military buildup along NATO’s eastern flank, conducted large-scale military exercises, violated the borders, airspace, and territorial waters of its neighbors, and intensified its propaganda efforts to undermine the governments of U.S. allies.

"And in the most flagrant demonstration of Putin’s disdain and disrespect for our nation, Russia deliberately interfered in our recent election with cyberattacks and a disinformation campaign designed to weaken America and discredit Western values," McCain wrote.

Read alsoDestructive effect of kompromat: Putin seeks chaos in U.S."Putin wants to be our enemy," McCain believes. "He needs us as his enemy. He will never be our partner, including in fighting ISIL." According to the U.S. Senator, Putin thinks that "strengthening Russia means weakening America."

"President Trump should remember this when he speaks to Vladimir Putin," McCain said. "He should remember that the man on the other end of the line is a murderer and a thug who seeks to undermine American national security interests at every turn."

"For our commander-in-chief to think otherwise would be naïve and dangerous," he concluded.