Sen. John McCain of Arizona accused fellow Republican Sen. Rand Paul of Kentucky Wednesday during a senate floor speech and stated that Paul was "achieving the objectives of" and "working for Vladimir Putin." 

McCain's statement accusing Paul came after Paul objected to a unanimous consent on a bill to support Montenegro's bid to join NATO.

In January, the U.S. Senate Foreign Relations Committee approved of a resolution that supported Montenegro's membership in NATO and sent it to the full senate for a vote. Two-thirds majority votes in the Senate are required for the approval of a new NATO member. Last year, the committee supported the small Balkan state's bid to join NATO; however a full senate vote did not take place. In January, McCain also assured Montenegro's Prime Minister Dusko Markovic over the phone that the Senate will approve of the accession soon, according to Business Insider

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During the speech Wednesday, McCain spoke about this resolution and showed his support and also warned his colleagues that anyone who would object it would be "carrying out the desires and ambitions of Vladimir Putin, and I do not say that lightly."

Referring to Paul he then said:"You are achieving the objectives of Vladimir Putin. ...trying to dismember this small country, which has already been the subject of an attempted coup."

Paul left the chamber after he objected to the unanimous consent on the bill.

Following this McCain said: "I note the senator from Kentucky leaving the floor without justification or any rationale for the action that he has just taken. That is really remarkable, that a senator blocking a treaty that is supported by an overwhelming number, perhaps 98 at least, of his colleagues would come to the floor and object and walk away. And walk away! The only conclusion you can draw when he walks away is he has no argument to be made. He has no justification for his objection to having a small nation be part of NATO that is under assault from the Russians. So, I repeat again: The senator from Kentucky is now working for Vladimir Putin."

Paul put forward his argument regarding his objection later in the evening Wednesday, CBS News reported. "Currently, the United States has troops in dozens of countries and is actively fighting in Iraq, Syria, Libya, and Yemen (with the occasional drone strike in Pakistan). In addition, the United States is pledged to defend 28 countries in NATO.  It is unwise to expand the monetary and military obligations of the United States given the burden of our $20 trillion debt," Paul said.

Paul and McCain never really agreed on issues, specifically the ones related to foreign policy.

In 2015 when Paul ran for GOP president, McCain called him "the worst possible candidate" on national security issues.

"John McCain is the guy that has advocated for war everywhere. We’re very lucky John McCain is not in charge because I think we would be in perpetual war," Paul said in an interview on ABC News last month.