SM Krishna recently resigned from the Congress.
"He (SM Krishna) has decided to join BJP, when we don't know, will fix it soon. He is joining 100%," said B.S. Yeddyurappa to news agency ANI.
Krishna served as Minister of External Affairs of India from 2009 to October 2012. He is a member of the Parliament in the Rajya Sabha. Krishna was the 16th Chief Minister of Karnataka from 1999 to 2004. He also served as the 19th Governor of Maharashtra from 2004 to 2008.
Mr Krishna who had been a stalwart in the party for nearly 50 years, was reportedly upset over being sidelined in the Congress.