McConnell said that, as of 2011, the Nunn-Lugar program has led to the deactivation of more than 7,600 strategic warheads, 791 intercontinental ballistic missiles, 669 submarine launch ballistic missiles, 32 nuclear submarines and 194 nuclear test tunnels.

"It's neutralized 1,395 metric tons of chemical weapons, and it has certified that the countries of the Ukraine, Kazakhstan and Belarus, which once had the third, fourth and eight largest nuclear arsenals in the world, respectively, are now nuclear free. What an incredible legacy."

Nunn-Lugar was passed with the cooperation of former Sen. Sam Nunn (D-Ga.), and is a program that McConnell said reveals Lugar to be an historic leader in the Senate.

"It's the mark of a leader that he thinks not only of his own moment in time, but of the future of his community and of his fellow man, here and around the world," McConnell said. "I think it's safe to say few senators embody that spirit as fully as Senator Lugar."

Sen. Dick DurbinRichard (Dick) Joseph DurbinTrump vows tougher borders to fight opioid epidemic Clinton: 'I meant no disrespect' with Trump voter comments Lawmakers rally to defend Mueller after McCabe exit MORE (D-Ill.) joined McConnell on the Senate floor and said the Nunn-Lugar program "may have saved the world from catastrophe time and again."

McConnell also praised Lugar for helping him win his first Senate seat in 1984.

"A lot of Hoosiers cross the Ohio River every day to work in Kentucky," he said. "But it's not often a Hoosier senator crosses it to help a Kentuckian make it in his first bid to the Senate."

McConnell added that Lugar's impressive six terms in the Senate followed an equally impressive earlier career, when Lugar was first in his class in high school and college, a Rhodes Scholar, a naval intelligence briefer, a corporate adviser and mayor, "and that was all by the age of 35."

"He has excelled at everything he has has ever done, and most incredibly, he's done it with perfectly smooth elbows," McConnell said. "Walk into any office on Capitol Hill and you won't find a single person who will say a bad word about Dick Lugar."