“We've planned a meeting,” he told Russian state news agency Tass.
Putin is expected to land in Brisbane on Friday evening in advance of the world leaders' meeting on Saturday and Sunday.
He understood Merkel well, he claimed.
“We're guided by our interests and not by personal sympathy or antipathy,” Putin said, adding that his relationship with the Chancellor has not been damaged by the Ukraine conflict.
Germany and other Western countries accuse Russia of supporting Ukrainian separatists with military equipment and personnel.
The Russian President used the interview to criticize Western sanctions against Russia.
But it would be “futile” to request a lifting of the trade restricitions at the G20, he added.