"Modji has given new status to India ... Today, India is on par with superpowers like United States, France, Russia and China. This has been possible because of the various programmes PM Narendra Modi has started," he told BJP workers at the state's party headquarters here.
The former external affairs minister said he was "impressed with Modi's courage to carry out surgical strikes".
"Modiji answered Pakistan in the language it understands. I had the privilege to meet him and he was kind enough to explain the contours of surgical strikes.
"I was impressed and this was possible only because of a leader who had guts, a vision and a strategy. Today, India has become very bold in the eyes of other countries," he said.
More From This Section
Krishna also praised Modi's demonetisation decision, saying that though it has not eradicated black money menace entirely, but has curtailed it.
He said he quit Congress because of bad treatment and the "mental torture" the party gave him.
"I was treated badly. All of a sudden, they dropped me from the cabinet. This is not the way you treat a veteran," he said.
Krishna said he had been thinking of quitting Congress for nearly two years and thereafter he met Amit Shah, the national BJP President, which answered all his queries.
At the party office, he was welcomed by State BJP President B S Yeddyurappa and R Ashok among others. The former Congress leader was welcomed amid the chanting of Ganapati Mantra.