Washington (CNN) - Sen. John McCain, R-Arizona, urged President Barack Obama again Sunday to re-evaluate the United States' relationship with Russia and to move past any notion of a "reset" with its old Cold War foe.
"The United States of America, first of all, has to have a fundamental reassessment of our relationship with Vladimir Putin," McCain told CNN chief political correspondent Candy Crowley.
Appearing on CNN's "State of the Union" just hours after returning from a Senate visit to Ukraine, the former ranking member on the Armed Services Committee swiped at Obama's dealings with the Russian president and reiterated his oft-stated belief that the White House remains woefully naive when it comes to Moscow.
"No more reset buttons. No more ‘Tell Vladimir I'll be more flexible,’" McCain continued. "Treat him for what he is - an individual who believes in restoring the Old Russian empire."
While cautioning that he does not want a "reignition of the Cold War" or to send American troops into Russian-occupied Crimea, McCain did call for some form of military assistance to the Ukrainian government.
"We need to give a long-term military assistance plan, because God knows what Vladimir Putin will do next," McCain said. "He believes that Ukraine is a vital part of his vision of the Russian empire. And we need to understand that and act accordingly."
McCain led a now-stalled effort earlier this week to push a Ukrainian aid package through the Senate. In addition to proposed sanctions against Ukrainians and Russians responsible for the violence against anti-government protesters, the bill featured $1 billion in U.S. loan guarantees and $100 million for enhanced security cooperation for Ukraine and some of its neighbors.
McCain offered more prescriptions for punishing Russia, including resuming the missile defense system in Poland and the Czech Republic, pushing Moldova and Georgia toward NATO membership, and economic sanctions.
The 2008 GOP presidential nominee predicted economic sanctions would be particularly damaging to Putin's interests, but said they would remain the most difficult to impose because of Europe's dependence on Russian energy supplies.
"Russia is a gas station masquerading as a country," McCain said. "It's a nation that is really only dependent on oil and gas for their economy, and so economic sanctions are important."
McCain's comments came as residents of the Crimea region headed to the polls Sunday to decide whether to join Russia or become an effectively independent state connected to Ukraine. Preliminary results from the referendum - which both the White House and U.S. allies in Europe have denounced as unconstitutional and illegal - could come as soon as Sunday night local time.
The Arizona lawmaker slammed the Moscow-backed referendum as "a bogus deal."
"We used to call it plebiscite in the days of Hitler and Stalin," McCain said.
Sunday's remarks come a day after McCain issued a call to action from Kiev and took aim at Obama on home soil.
Speaking in the Ukrainian capital on Saturday, McCain called providing military aid to Ukraine "the right and decent thing to do." Though the senator refrained from criticizing Obama while on foreign soil, he excoriated the President in a New York Times op-ed.
"Crimea has exposed the disturbing lack of realism that has characterized our foreign policy under President Obama. It is this worldview, or lack of one, that must change," McCain wrote.
CNN’s Cassie Spodak contributed to this report.