Republican Sen. John McCain of Arizona has accused fellow Republican Sen. Rand Paul of Kentucky of working for Russian President Vladimir Putin.
The allegation came after Paul indicated his opposition in the Senate to a bill that would have agreed to the country of Montenegro joining NATO, the Washington Examiner reported.
"If there's objection, you are achieving the objectives of Vladimir Putin," McCain said, according to the Examiner. "If they object, they are now carrying out the desires and ambitions of Vladimir Putin, and I do not say that lightly."
This warning did not stop Paul, who declared "I object," before leaving the chamber.
McCain commented on the incident from the Senate floor immediately afterwards.
"That is really remarkable," he said. "That a senator, blocking a treaty that is supported by the overwhelming number, perhaps 98 at least of his colleagues, would come to the floor and object, and walk away."
McCain alleged Paul had done so because he had no argument against supporting the measure.
"The senator from Kentucky is now working for Vladimir Putin," McCain alleged.
Paul rejected this charge and released a statement on his opposition to accepting Montenegro into NATO.
"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)," added Paul. "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," he said.
A statement by a McCain spokesman appeared to back off somewhat from the Senator's allegation.
"Senator McCain believes that the person who benefits most from Congress's failure to ratify Montenegro's ascension to NATO is Vladimir Putin, whose government has sought to destroy the NATO alliance, Erode confidence in America's commitments to its allies, overthrow the duly elected government of Montenegro and undermine democratic institutions throughout Europe," the statement read, according to the Daily Beast.
Russia has been accused by British intelligence sources of plotting a coup in Montenegro and possibly even the assassination of pro-western Prime Minister Milo Djukanovic. On Oct. 16, 2016, authorities in Montenegro arrested 20 people accused of plotting to take over the parliament building and attack civilians.
Montenegro was invited to join NATO in December 2015. All 28 member states must approve its membership before it can join as a full member.
Russia has denied the accusations of interference in the country. Kremlin spokesman Dmitri Peskov described them as unsubstantiated and irresponsible, according to Sputnik.