"He doesn't realise the truth," Wantuch told The Associated Press. "He doesn't understand what is going on in Ukraine."
Polish media on Saturday had reported that the gigs were cancelled by Waters' management, in reaction to the outcry over his views. Waters denied that on Sunday and Wantuch confirmed that Krakow and the venue made the decision to cancel the concerts.
Wantuch, who has been on 27 humanitarian missions to Ukraine since the war began, spearheaded a symbolic resolution to declare Waters "persona non grata" in this city. A vote is scheduled to take place.
Wantuch invited Waters in an open Facebook post to join him on a visit to Ukraine to see for himself the extent of devastation caused by Russian attacks.
In a Facebook post on Sunday, Waters accused Wantuch of a "draconian censoring of my work".
He said: "Wantuch seems to know nothing of my history of working, all my life, at some personal cost, in the service of human rights."
Waters has blamed both Nato and Ukraine for the war.
He wrote an open letter to Ukrainian first lady Olena Zelenska this month in which he blamed "extreme nationalists" in Ukraine for having "set your country on the path to this disastrous war". He also criticised the West for supplying Ukraine with weapons, blaming Washington in particular.
He has also openly sided with China on the issue of Taiwan.
Wantuch wrote in his open message to Waters that with 2.6 million followers on social media, he had the power to influence many minds.
"You are calling on the West to cease military aid, which in fact means the capitulation of Ukraine," Wantuch wrote. "Ukraine will not give up, it will fight, but because of people like you, because of what you say and write, it will be a much harder fight."
- AP