Sen. John McCainJohn McCainMeghan McCain: Obama 'a dirty capitalist like the rest of us' Top commander: Don't bet on China reining in North Korea Trudeau, Trump speak for second night about US-Canada trade MORE (R-Ariz.) on Sunday called the referendum in Crimea to gain independence from Ukraine and join Russia "bogus."
He said Sunday's vote is already a done deal.
McCain and the U.S. ambassador to Ukraine have a running bet on how lopsided the vote will be. McCain thinks the referendum will be approved with 70 percent of the vote.
Ukraine’s ability to regain Crimea now will have to be a long-term goal, he said.
"What I would like to see is a long term commitment to the freedom, democracy and the assistance we can provide Ukraine, including, over time, regaining Crimea," he said.
McCain and seven other senators are just back from a trip to Ukraine where they met with leaders of the country's new government.
McCain said the question now is whether Russia President Vladimir Putin decides to moves troops into eastern Ukraine. The United States needs to start treating Putin "for what he is," a leader who wants to restore the old Soviet empire, McCain said.
"The United States of America, first of all, has to have a fundamental re-assessment of our relationship with Vladimir Putin. No more reset buttons, no more tell Vladimir I'll be more flexible," he said.
McCain has argued for the U.S. to provide military assistance to the Ukraine, something the administration has resisted. McCain said he has talked to Secretary of State John Kerry and "they are giving it serious consideration."